Olds Smog 307 to '71 Rocket 350 Engine Swap

I called on that 403 in town and it sounds really good. I think I'm going to get it. I posted the below thread on the G-body forum, but thought I'd post it here too. I know a lot of folks here had the 80's 307-engined wagons and someone may have done this swap. Started a new thread so the "lurkers" might see it.

Here we go:

I know there are a lot threads about this swap, but can someone give me the complete "parts list" for this swap?

My car is an '88 Cutlass Supreme Classic, stock 307 and 200R4 transmission, floor shift car. I've got the opportunity to buy a '77 403 out of a full size Buick.

I'm on a super tight budget for this swap right now. This came at a bad time. I don't plan to hop up the 403, but I do plan to re-seal it, install a new oil pump, timing chain and gears, water pump, then clean it up and paint it, and will detail the engine compartment while it's out. I just want it to look good and be reliable.

My stock 200R4 is a weak link here, and I know it. I want to retain the overdrive, and the trans shifts fine now, so I'm going to cross my fingers. I don't plan to hot-rod around in this car, it's just a cruiser, so hopefully the little transmission will hold up for a while.

I want to retain my CCC so I can keep my Cruise Control and TCC in the transmission working, but I know the VIN 9 "roller" 307 intake won't work on the 403. If I get an early 80's 307 intake, can I use my current carburetor and will everything else bolt up?

I've read all the pulley's and mounts off the front of the 307 will work fine on the 403. How about the 307 flywheel and starter? Also what do I do about the exhast manifolds? Anyone know if the Cutlass exhaust pipes will bolt up to the 403 manifolds? The 307 manifolds are tiny, the 403's look larger. I am planning to add cat-back dual exhaust after doing this swap, but for now it's going to have the single. Will it bolt up?

I really want to gather all the needed parts together so I can do the swap over a weekend with some help from my friends.

Any tips or a list of parts to grab are much appreciated!

Please help me bring my pretty little Cutlass back to life!

-Mike

Here's some tips,. see what gaskets are leaking and replace them,.

grab the front balancer and see ho much slop is in the chain,. anyting more than 10deg total (+5-5) add a new timing chain, don't worry about the gears, UNLESS it has a nylon covered cam gear,..(new front seal and gasket,.)

leave the oil pump alone,.(why are people obsessed with oil pumps!!!)

put it in,.

403 carb should have the right brackets for the trans etc,.

PUT a transgo kit in the tranny,.

drive it.
then see if it needs a tune up,.

Nick
I prefer to use a used oil pump to a new one,. the quality control on stock aftermarket oil pumps is horrendous,.

Nick you wouldnt pull the pan for a quick inspection?

Flasheroo wrote:

Nick you wouldnt pull the pan for a quick inspection?

depends on the seller,. and what he was selling,.i.e a good runner,.
or a 'core'
Mebbe Throw the starter on it,. crank it over with no plugs,. make sure its got pressure,.

It's been my experience once you start looking,. you'll talk yourself it a refresh/rebuild,.mikes OCD will kick in,.
let him paint it,.fire it up,. drive it.
M2C

Nick

Thanks for the comments. I didn't know there were issues with new oil pumps, but that's good to know. I'm going to pull the pan to do the rear main and will see what it looks like inside.

I figure if I can work out a deal with the seller I'll put the 403 on the stand I have in the garage, replace all the gaskets and seals, most likely do the cam and gears because I've since found all the Olds use those nylon-covered gears from the factory, install a new water pump, and it looks like I need to use a 1980-85 307 intake to retain my CCC.

I just did a full tune-up on the 307, so hopefully all that will transfer to the 403. Will see. I know I'll be using the 307 distributor since it's computer controlled and the 403 was vaccum.

I've not decided yet if I'll paint it Olds Gold or just go with black like the 307. 403's came from the factory painted blue...yuck. And yes I'm going to dork-out with the chrome Olds valve covers I bought when I had my 89 Custom Cruiser but never installed. Will keep it original other than those. Yo-Yo-Yo...ha. Will re-use my 442 air cleaner I have on there now.

I hope I can work out a deal with the seller. I'm just itching to yank that 307 out now....

-Mike

The engine blue is nice. You crazy, Mike.

60's Pontiac silver/blue was nice.....70's GM generic blue was boring...

-Mike

The Cadillac guys say to NOT use the computer distributor on the 403. They suggest a regular HEI unit, along with a non-computer carb.

jayoldschool wrote:

The Cadillac guys say to NOT use the computer distributor on the 403. They suggest a regular HEI unit, along with a non-computer carb.

I'd LOVE to get rid of all the computer crap but how do I engage the a/c, cruise control and torque converter lockup without keeping it original?

I was trying to keep this and "plug and play" as possible.

That being said you can not even see the valve covers on the 307 for the wire and vaccum hose speghetti under there. You open the hood on the 70 Buick and you can see almost all the entire engine thanks to no computer in 79. I'd LOVE it if my Cutlass looked like that.

Oh and the guy with the 403 called me back. I'm going to go down there this weekend and see the engine. It's about 45-mins away. It sounds like a good engine so if I can work out a deal I may have a new toy in the garage for the holiday weekend. We'll see!

-Mike

I don't know the specifics, since I was so young, but I do know that our Cutlass back in the day still had functioning AC and cruise. It's doable. I'll see if I can convince dad to chime in tonight when he gets home from work.

Thanks! I think you have to ground the a/c some way to engage the clutch...I'm sure I can figure that out, but the cruise control and torque converter lockup issues concern me.

Stingroo wrote:

I don't know the specifics, since I was so young,

WAS?!?! What do you mean "was" so young? Hell, my YOUNGEST son (you remember Dustin?) is older than you........


Sheesh, KIDS nowadays.....

[/rant]

81X11 wrote:

I'm going to pull the pan to do the rear main and will see what it looks like inside.

replace all the gaskets and seals, most likely do the cam and gears


I'm going to dork-out with the chrome Olds valve covers Will re-use my 442 air cleaner I have on there now.

I hope I can work out a deal with the seller. I'm just itching to yank that 307 out now....

-Mike

Leave the rear main alone, unless its already slobbering,. to do a rear main seal you need to pull the rear main bearing,.
cam and lifters??? wtf?? check olds prices for new cams and lifters,. bigger cams need valve springs,. and proper break in yada yada,..want a cheap upgrade? go get a used stock 455 cam buy some new lifters,.run the cam at least 4 deg advanced,. that 403 will wake up nicely,.stock valve springs won't mind, it'll be torquey and make lots of vacuum,.


new gaskets???? what wrong with the old ones??

wtf ??
307 distributor???? good grief! stay away from that computer controlled crap fer crying out loud,.
recurve the original,.

gotta use a 307 intake because you can't fab a tin bracket?? 307 intakes crack bad,. and check your 403 port sizes against the 307's,.
stick with the 403's carb,. pour a little brake fluid into the vent hole, fill up the float bowl,. and let it sit for a day,. then squirt it thru the acc pump,.till she's empty,. she'll be good to go when it fills up with fuel,.

jeez,. you might as well castate the poor motor and add the 307 exhaust manifolds,.

Just visually check it to see its good, worry about other stuff later,.
after the first oil change,.( 1 week of driving),.put in some lucas oil additive to soften the seals and gaskets nicely,. give everything just a quick check tighten,.do the chain and gears if its loose,.
BOLT IT IN,..

might as well do the water pump,.
boil out the block and do cam bearings too,. re-hone it ,. a set of rings,. new head gaskets,. add some head studs because we all know olds motors lift the heads easy,. add a new starter,. alternator should be done too,.a new flex plate because you're already there,.mains studs,. you're already in the pan and everybody knows the tall olds mains walk around,.


dude,.

you,ve no money in one post and are off to buy a decent?? motor to put in the car,.on a budget,. in the next your $500 worth of stuff that doesn't need doing,.

oy vay,.

stick to finding them,.thats your forte,.

It,s your car and your motor,. but you solicited opinions,. and this is mine,.

good luck.

jm2c,.

Nick

Mike there is a good chance all that stuff has already been replaced.I am with Nick here,new
cam done right requires valve springs,then keepers,then rockers,then pushrods.then lifters.
proper break in and break in oil.List go's on and on.Slow down dude and go 1 step at a time
before it turns into a money pit because of you and not because the engine needs it.

Krzdimond wrote:

Stingroo wrote:

I don't know the specifics, since I was so young,

WAS?!?! What do you mean "was" so young? Hell, my YOUNGEST son (you remember Dustin?) is older than you........


Sheesh, KIDS nowadays.....

[/rant]

LOL Well I was like six or seven when the Cutlass underwent its engine swap. All I did was hand over sockets and such. I was younger.

307 to 350/403 swaps are easy(from experience):

*Go off the computer. You'll have to adapt the AC control and the TCC lock-up function. Mid-80s GM trucks used a vacuum switch arrangement to operate the TCC, looks factory.

*Use the regular HEI with vacuum advance. One out of any Olds V8 will work.

*Throw the 307 intake and exhaust manifolds as far as possible. The '85-up 307s have tiny ports on swirl-port heads. Use the old iron stuff intake and exhaust found on the bigger engine.

* Use a 77-79 Oldsmobile quadrajet, it has all the cable hookups and vacuum ports in the right spots already. Other versions might not clear the EGR.

The numbers to look for are 17057251 2 or 3, 17058251 2 or 3 and 17059251 2 or 3

*When you go look at that 403 make sure it is one. Look for 4A cast on the lower left corner of each head, and 557265 553990 or 554990 for the block casting number between the waterpump and intake.


Anything else and it isn't a 403.

phantom 309 wrote:

81X11 wrote:

I'm going to pull the pan to do the rear main and will see what it looks like inside.

replace all the gaskets and seals, most likely do the cam and gears


I'm going to dork-out with the chrome Olds valve covers Will re-use my 442 air cleaner I have on there now.

I hope I can work out a deal with the seller. I'm just itching to yank that 307 out now....

-Mike

Leave the rear main alone, unless its already slobbering,. to do a rear main seal you need to pull the rear main bearing,.
cam and lifters??? wtf?? check olds prices for new cams and lifters,. bigger cams need valve springs,. and proper break in yada yada,..want a cheap upgrade? go get a used stock 455 cam buy some new lifters,.run the cam at least 4 deg advanced,. that 403 will wake up nicely,.stock valve springs won't mind, it'll be torquey and make lots of vacuum,.


new gaskets???? what wrong with the old ones??

wtf ??
307 distributor???? good grief! stay away from that computer controlled crap fer crying out loud,.
recurve the original,.

gotta use a 307 intake because you can't fab a tin bracket?? 307 intakes crack bad,. and check your 403 port sizes against the 307's,.
stick with the 403's carb,. pour a little brake fluid into the vent hole, fill up the float bowl,. and let it sit for a day,. then squirt it thru the acc pump,.till she's empty,. she'll be good to go when it fills up with fuel,.

jeez,. you might as well castate the poor motor and add the 307 exhaust manifolds,.

Just visually check it to see its good, worry about other stuff later,.
after the first oil change,.( 1 week of driving),.put in some lucas oil additive to soften the seals and gaskets nicely,. give everything just a quick check tighten,.do the chain and gears if its loose,.
BOLT IT IN,..

might as well do the water pump,.
boil out the block and do cam bearings too,. re-hone it ,. a set of rings,. new head gaskets,. add some head studs because we all know olds motors lift the heads easy,. add a new starter,. alternator should be done too,.a new flex plate because you're already there,.mains studs,. you're already in the pan and everybody knows the tall olds mains walk around,.


dude,.

you,ve no money in one post and are off to buy a decent?? motor to put in the car,.on a budget,. in the next your $500 worth of stuff that doesn't need doing,.

oy vay,.

stick to finding them,.thats your forte,.

It,s your car and your motor,. but you solicited opinions,. and this is mine,.

good luck.

jm2c,.

Nick

I meant replace the timing chain and gears....not the cam and gears. I really didn't want to tear the engine down, just was planning to re-seal the oil pan, head off any leaks by doing the front and rear main seals....if I could get at them. New valve cover gaskets and new valve covers.

I want to use the 403 exhaust manifolds.

Such fun.

-Mike

I can't believe how much good info I've received over the past few days regarding this swap. I have no idea what people did before the internet. This is not something you could just go to the library for!

I was just sent this info. Loving this:

There's 2 black connectors that plug into a clear/white connector near the ECM. The clear/white connector is part of the ECM harness and this entire harness can be removed. When you remove this ECM harness, the 2 black connectors and all the wires that go through the dash will still be there.

Look at the 2 black connectors. They are lettered. Pin 'M' should be a black wire with a white stripe. This is the ground for the 'Vechical Speed Buffer' which is needed for cruise control. Just ground this wire and you'll retain cruise.

Pin 'P' should be purple. Get a Painless converter lockup kit and run it to this wire. You'll have converter lockup without even having to bother with the included brake switch from the kit because the G-body's already have it and it's allready wired up for you from the factory. This is why you just have to hook the Painless kit ( a purple wire ) to pin 'M' ( a purple wire too ).

Pop the circuit board out of the 'remote lamp driver' ( greenish colored plastic box wired into the ECM wires going through the dash and located behind the glove box ) and this will make the 'Check Engine' light go out.

Also found out the 403 exhaust manifolds will mate up to the stock 307 Cutlass exhaust system. I'm sure that single exhaust is really restrictive, and will put duals on it soon after, but at least I know I can get the car running without having to replace the pipes when I do the swap. Baby steps!

-Mike

Going to look at that 403 tomorrow way down southeast of town.

Also found a guy selling a running Olds 350 right here in town. He wants a little more for the 350...but it's running and that 403 is sitting on a crate with a tarp on it...it was pulled a year ago.

I'm beginning to lean toward the engine I can hear running, but we'll see!

-Mike

Well that was short-lived. The guy with the 350 wants to keep the heads and intake, so it's basically a short block. Crap.

Back to 403's I guess.....

http://dallas.craigslist.org/dal/cto/2471307093.html - Hmmmmmmm

81X11 wrote:

http://dallas.craigslist.org/dal/cto/2471307093.html - Hmmmmmmm

There you go, and I think that might actually be a Holiday coupe.

I dare say - I think you've found your Cutlass motor.


Plus you could scrap the body and recoup much of the initial cost anyway. Win win.

Just hope Misty doesn't shoot you. Hide the guns!

Well I bought an engine....actually it kinda fell in my lap. One of my buddies that has a restoration shop got in a 71 Cutlass Supreme with a good running Olds 350 in it. He's going to do a 455 swap in it, and had no use for the 350.

Made the deal this weekend. Ran the numbers and it's the original 71 "Rocket 350" with #7 heads, which came from the factory with unleaded-friendly hardened valve seats.

It's been "updated" with an Edelbrock intake, electronic ignition, and an aftermarket carb, plus the usual "Pep Boys" dress up stuff. It's filthy, and I can't tell if it's ever been rebuilt, but it runs great, no smoke or noises, good compression, and has good power. Should be quite a step up from my gutless 307.

He wants to keep the carb and distributor, but I get everything else. Will be pulling it this week, and then I'm going to bring it home and put it on my engine stand, stare at it, and decide the next steps.

Progress!




-Mike

I see Cadillacs in that picture, what the scoope on those?

Why waste time dicking around staring at it? Get an HEI dizzy and a new carb and PUT IT IN YOUR CAR.

buickestate wrote:

I see Cadillacs in that picture, what the scoope on those?

Both are projects, the Eldorado is on hold, but the 68 DeVille will be heading inside soon.

I need to get some pics from this guy's shop. He's got tons of old stuff in there you'd love.

Such fun!

-Mike

Bewber wrote:

Why waste time dicking around staring at it? Get an HEI dizzy and a new carb and PUT IT IN YOUR CAR.

I'm going to clean it all up, pull the valve covers and oil pan, and see what it looks like inside. Got to decide if I want to rebuild it while it's out or just re-seal it and dump it in. Also debating about keeping all the computer stuff hooked up or pulling all that crap out.

Lots to decide. Will get it home next weekend, de-grease it on my stand and go from there.

Besides, I'm not going to yank the 307 until this fall. It's WAY too hot to do an engine swap new. Today is day 30 of 100+ temps here in Austin. We've blown every record out of the books for heat and drought this year. It'll be mid-September before I start yanking 307's. For now I'm going to take a hard look at the engine and decide how far to go on it, gather needed parts, and get it ready for fall.

I am tickled I found an early 350. From what I've read these are the perfect engines for G-bodies, since everything bolts up, they weigh less than the 403, make good reliable power and breath really well.

I've already ordered my Rocket 350 air cleaner decal. Ha!!

-Mike

So do I paint the engine 70's blue, 80's black or original 60's gold??

I'm leaning toward gold...with some smooth non-label chrome valve covers and my stock 442 air cleaner with the Rocket 350 decal on it's chrome lid.

Ahh dreaming... I'm ready to get my hands dirty on this.

-Mike

If it runs strong and doesn't smoke, LITFA.

It seems to run great, it just looks ratty.

BUT since I'm doing all this work I'm determined not to rush and to do it right. I just want a good running and reliable engine for my t-top toy.

Put it on an engine stand, put two cans of engine degreaser on it, clean with a pressure washer, paint, install.

GOLD, btw.

Also, I highly recommend another of those Edelbrock carbs. I run one on my 71, and it has worked great for 15 years. The 1406 would be the right one for your 350.

Jason.

Thanks Jason!

A true Rocket. Nice score!

Now go for the gold.

If its got good compression and oil pressure just clean it up Mike and install then enjoy it.Why
do you overthink/complicate things so much.Just make it purty like we know you will but stay
out of that motors insides Mike.

Because if it isn't broke, ole Texas Mike fixes it until it is!

Flasheroo wrote:

If its got good compression and oil pressure just clean it up Mike and install then enjoy it.Why
do you overthink/complicate things so much.Just make it purty like we know you will but stay
out of that motors insides Mike.

Bewber wrote:

Because if it isn't broke, ole Texas Mike fixes it until it is!

I can almost hear bill murray playing the piano here,.

Mikey as stated,. stick to what you're really good at ,. clean it,. paint it, detail and put it in,.make it look like brand new,.

Go to the local pick and pull,. grab an HEI dizzy for your buddy so we don't have another 5 page thread on getting another distributor back into its hole,.(in the right spot)

step up and buy a nice NEW edelbrock carb,.(750cfm) with a nice inline gas filter between the mechanical pump and the carb,.
put some nice light springs in the distributor thats in the motor now,.
DO NOT USE THAT PILE OF SCRAP 1/2 and 1/2 CARB YOU HAVE ON THE 307,.


Mebbe it's you that needs to be re-sealed? (insert obligatory laughing smilie << here)

JMHO of course.
Nick

phantom 309 wrote:

Go to the local pick and pull,. grab an HEI dizzy for your buddy so we don't have another 5 page thread on getting another distributor back into its hole,.(in the right spot)

step up and buy a nice NEW edelbrock carb,.(750cfm) with a nice inline gas filter between the mechanical pump and the carb,.
put some nice light springs in the distributor thats in the motor now,.
DO NOT USE THAT PILE OF SCRAP 1/2 and 1/2 CARB YOU HAVE ON THE 307,.

Gotta agree with this 100%

Nice score on the 350

Tell them to get those wheels off that Cutlass now, they are FUGLY.

I'm 99% sure I'm going to get rid of the ECM, wiring, 10,000 vacuum lines, smog pump and hoses. That will clean up a lot under the hood and make the car much easier to service.

I figure an HEI distributor from a 79 or older Olds V8 will work. Will run to Pick-N-Pull for one.

I would much rather have a new Edelbrock carb than another Q-jet, so yes I think I'll suck it up and buy a new one. Just have to make sure the linkage for the transmission and cruise can be mated to it. I "think" my 200R4 has a "TV cable" like a 700R4, and if those are not set right I know the transmission will fry.

SO that leaves setting up the cruise control, getting the aftermarket kit for the electric lockup on the torque converter, and grounding the a/c compressor so it'll engage once the computer goes bye-bye. Oh and a custom dual exhaust system, since I'm getting the 71 Cutlass manifolds in the deal.

And yes the engine will be gold...it is now under the grunge. Will make it pretty again....can't wait to do that part.

As to my "overthinking" things, the valve covers are ugly and rusty, so those will be replaced and new gaskets installed. The oil pan is wet, so it'll need at least a gasket and at most a rear main seal. Will also put all new tune-up parts, hoses, and a new water pump and t-stat on it while I'm doing the job.

Such fun! He's promised to have the engine out by Friday the 22nd, so I'll get it home that weekend and put it on the engine stand and get every hit of grime off it, and go from there!

-Mike

Mike if you stick with the edelbrock carb,I think its Lokar that makes an adapter so your cruise
and the trans hookup just like from the factory.Please just fix whats broke and do your cleaning
thing.I will go thru my Lokar catalog for that number.

Thanks Jim

Nick mentioned a 750 carb, but when I go to Edelbrock's site for a stock '71 Olds 350 they say a 600cfm is correct, and hype the 1406 model carb.

I'm going to see what model is coming off the engine now. It ran great when I fired it up over the weekend. Will try to find the same thing.

-Mike

1406, like I said. The correct carb for a 350, speaking from experience.

So 600cfm, ok good. I'm starting a parts list, and this is at the top.

-Mike

1405 if you want a manual choke. You really don't need a choke if you never drive in cold weather.

Great choice

Like everyone is saying, clean it, paint it, drop it in. Don't intentionally turn a good running engine into another money-pit pile of parts.

And a heads-up: the parts store Gold engine paint is NOT the right shade. Eastwood and Fusick have the right shade.

Thanks for the tip on the paint! Added to the list.

And it actually does get cold here some in the winter, so I want the automatic choke. Had a manual choke on my old 78 Silverado Big 10 and hated it.

Fun-Fun! I don't get the engine until the 23rd...it's still in that '71 Cutlass but it should be out shortly.

-Mike

FWIW, I also REALLY support Nick's suggestion about leaving that dizzy in THAT motor and buying the new one for your friend to use in his project.