Olds Smog 307 to '71 Rocket 350 Engine Swap

Latest Update:

I'm sitting here flabbergasted. Neil just called. He's had the car two days, and in those two days has it almost all sorted out. I'm really amazed...it's all in getting someone that knows what they are doing!! (not me I guess...ha)

Engine Work:
- Installed the new aftermarket distributor, set the correct timing
- Adjusted the new Edelbrock carb
- Found a vaccum hose that was leaking, replaced, idles smooth now.
- Found coolant leaks at the t-stat housing and lower hose. Fixed.
- Put a notch in the Edelbrock intake manifold and made up a new rod for the cruise control from the diaphram to the carb.

Electrical Work:
- He cut the ECM harness off and totally removed it from under the hood. Says it's great to SEE the engine.
- Pulled rest of ECM harness out through the firewall and removed ECM altogether from the under dash kick panel. Welcome to 1971 again!
- Ran new power line from stock dashboard ECM wiring through the firewall grommit for the electric choke
- Removed the circuit board out of the 'remote lamp driver' and now the Check Engine light is out.
- Jumped the wires under the dash on the ECM wiring to ground the a/c compressor
- Did the wire mod for the cruise control so it reads the speedo speed sensor again

He said the car runs great now. Hahahaha! Starts easy, good idle, good power. Wow! I can't wait to drive it! Said he hit the cruise control at 45mph and it came right on and held fine...that's NEVER worked!! Hahaha!

He gave me a great price for all that work too. Worth every penny!

He DID say I need to put a Monte SS/442/Grand National rear in the car, as the current 2.56 or 2.73 rear is silly. He says I HAVE to replace that single exhaust. Haha, I know, as time and money allows that WILL be done. He thinks the older aftermarket cat may be clogged. With the exhaust and rear he said it'll be quick. For now, he said I'll like it a lot better regardless.

He also said the a/c compressor is coming on now, but is cycling. Car is still R-12, and he's not set up for that, so will take it to my a/c friend to top it off. I didn't discharge it when we did the motor swap, just layed it to the side. I'm sure it's just a tad low. I'm just tickled it's coming on now!

Car is going to Ricky at Aamco Transmissions next for the TCI overdrive mod for the 200R4. That'll be in two weeks. For now I'm going to just use 3rd gear to get the car home, and planning to do a big clean-up and detail under the hood. Pics soon.

I WILL be sending Neil business. Just can't say enough about his work and his speed!

Getting excited now.

-Mike

Great news, Mike!
Can't wait to hear about your first ride with the new and improved powertrain.

Awesome news Mike,after all this time you no longer have a gutless Cutlass!WOOHOO!

Well it's payday and I was supposed to pick up my Cutlass from Neil this morning, but as usual, had an issue. Neil said he went to start it up this morning to pull it out of the shop, and he heard a pop that sounded like a fuse blowing in the dash, and the blower stopped working. Doh!

He checked the fuse block and all the fuses are good. Now he's pulling out the radio and climate control head to see if something back there burned up.

It never fails! Hope he sorts it out today....I was hoping to take it to the cruise-in tomorrow night. Been over a year since I've had it at the cruise-in.

-Mike

Didnt think it would really be this easy did you?

Just had a HOT (96-degrees here today) but happy drive in my Cutlass! IT IS ALIVE again....only took....well...a year....

Pics below....please understand I've not so much as wiped off the air cleaner yet. Will be cleaning and detailing under the hood this weekend...but after a year, figured it was time for pics!

So here we go. Neil gave me a good walk-through of what he did. ECM and wiring are in a pile in the trunk. You can SEE the engine under the hood now!

It runs, idles and drives GREAT. Much more power than the 307. Still not a monster, but the single exhaust and rear gearing suck. Will fix those soon!

He showed me the old distributor...and it was shot. Weights stuck. My fault, tried to go with used parts. New distritutor is in. Timing is set at 12 and advances to around 28. No ping, no hesitation. Starts easy, even hot.

Cruise control arm modded and and mounted to new carb. Wiring modded to work without the computer. Works like new. Set cruise at 70mph....holds fine!


Check engine light is out FOREVER!

A/C wiring fixed, and blower works again. Had a short in the blower switch, that's fixed too. Compressor is cycling...needs a charge, still R12. Will charge shortly. Does cool, but not COLD like it needs to be. Wiring done, and I can do the rest!

He also re-gapped the spark plugs. I put new 71 Olds 350 plugs in, gapped to the '71 specs I found, and he said they needed a bigger gap with the electronic ignition.

Lastly he tightened up the thermostat housing....I didn't have it tight and it was seeping, and replaced the lower radiator hose, which had a pinhole in it. I missed that as well.

Only a couple of outstanding issues (beyond how dirty the engine bay still is). I still have to order a lockup kit for the 200R4 transmission, so driving home I had to keep it in 3rd gear, and the other issue is it ran a bit hot going down the road. Averaged 220-240, and I know I have a 195 thermostat in it, and it has a new water pump. With the 307 it never went up to even halfway on the gauge. Was too hot to check the coolant when I got home. I hope it's just not topped off. Will check tonight.

Here's some pics!

On the road again!




Nasty old 307



Plan A. 350 installed....trying to keep the 307's carburetor, ECM computer, wiring, hoses and smog stuff. Ran like garbage, could not see the engine for all the hoses and crap. FAIL!!! Yanked it all off.



Plan B. 1971 Rocket 350 installed, NO computer/hose mess anymore, new Edelbrock carb and vaccum distributor. You can now SEE the new engine!




Old '88 307 at idle, in gear. No oil pressure


New 71 350, Oil pressure at idle in gear


Old 88 307 oil pressure while driving



New 71 350, Oil pressure while driving


Next pics will be after underhood cleanup and detailing.

-Mike

Congrats, Mike. It's good to see a project come together!

Cool. Now you can get rid of your 67 goat. I'll buy it from you, to make things easier.

Mike,sent you a PM about your having to use a high zinc oil with the performance flat tappet engine.You will round off that cam with todays extreme low zinc oil in just a hundred miles
if not sooner.

Congrats! So you will make the cruise now?

I'm running Castrol GTX high mileage. The engine, as far as I know, is a stock rebuild. I sure hope I'm not going to have issues. I know most of the folks in my local car club are running GTX in their old cars with no issues.

There's always the GM ZDPP additive.


Mike - no video of the beast? I'm almost disappointed!

Yeah!... What he^^^ said!... HD video!

It still has the stock 307 single exhaust....only mod was 403 manifolds. It's so quiet you almost can't hear it running. I also think the cat converter may be a little plugged. Will fix that soon. A video would not be to impressive.....unless you like a quiet motor.

That said, I just got back from the friday night fireworks at the Dell Diamond ballpark. Dad showed up, and we took my 3yr old. Took the t-tops off the Cutlass and parked way at the back of the parking lot, right on the edge of the field where they shoot them. Got a great show through the t-tops!! Man I missed this car!

That said, the idle is still a little low...feels almost like it's going to stall when stopped in traffic waiting to get out after the show. Never did stall, but felt close. Also, I checked the coolant and it wasn't low. Tonight it never got up above about 210 on the gauge....but it is nighttime.

Dad was impressed with it. I got on it just a bit coming back and it sure has more power than it did.

Still have some tweaking to do but I'm tickled it's back on the road!

-Mike

jimbeau wrote:

Cool. Now you can get rid of your 67 goat. I'll buy it from you, to make things easier.

Thank you for thinking of me like that..... I can't get rid of the GTO....what would I pile my crap on in the garage???

Took the car to the Cedar Park cruise-in tonight (pics in the Events section) and the gauge never got hot, stayed around 180-205.....good deal! Guess it just has some air in the system that had to work itself out. Will check the level tomorrow.

Car is running GREAT! I can't believe Olds never offered the 350 in these....307's are SO WEAk in comparison, this car has SO much more power and since you don't have to floor it to make it go, I bet the mileage is ok too! We'll see soon.

Having fun with this toy now!

-Mike

SO I sold Misty's Grand Prix, but we've not bought her a new car yet. She's driving my Ram, and I'm actually commuting to work in my Cutlass. Never planned on that. Had to strap the kid seat in the back so I can drop off at daycare...looks funny in that car.

I re-charged the a/c Monday....man R12 is EXPENSIVE now, but it's blowing cold. I also got a big piece of cardboard and made me some t-top shades. Painted them silver on one side to reflect the heat and flat black on the bottom, which is what you see in the car. I need to get some REAL ones made out of headliner material, but for now, this works.

You’d be amazed what a difference the t-top shades made in the Cutlass! It's dark in there! It can now actually be used in the summertime in Texas...like a real car! Ha! Before it was like sitting under sunglasses, you just baked, and the a/c had no hope of keeping up in the afternoon. I ran errends after work in it yesterday, and after running it just a bit, it cooled down nicely inside. Wild!

The vents by the gauge cluster blow pretty strong….enough so that you can feel the a/c on your face. The long passenger side vent above the glove box though has almost no pressure. I opened the glove box door and dropped it down, and there is a bad seal or something in the ductwork in there. The INSIDE of the dashboard is getting all the a/c on that side...I could chill Cokes inside the glove box. Will see if I can sort that out this weekend.

In other news, the car is going to Taylor Muffler on Monday. Sadly, the new hippy tree-hugger law here requires a catalytic converter on vehicles 1983 and newer, even though after 25 years they no longer do the smog test itself. SO I’m getting a free-flow cat installed, than a Y-pipe to dual turbo mufflers, and dual pipes with chrome tips exiting behind the rear wheels, 80’s 442/Grand National style. Even though it will not be true duals, I bet it’ll sound a lot better.

Also, I changed the oil to Exxon high-mileage 10W30...which I'm told has more zinc in it for flat-tappet engines. Seems to run fine but plan to keep the oil changed often.

Coming along!

-Mike

Glad to see this car running and being used. I spent all of my childhood years in a car seat in the back of a G-body Cutlass.

Stingroo wrote:

Glad to see this car running and being used. I spent all of my childhood years in a car seat in the back of a G-body Cutlass.

This was just last week wasnt it Ray?

Car's been gone for over a decade now... I can hardly believe it. It's honestly almost enough to make me cry. I miss our Cutlass.

81X11 wrote:

jimbeau wrote:

Cool. Now you can get rid of your 67 goat. I'll buy it from you, to make things easier.

Thank you for thinking of me like that..... I can't get rid of the GTO....what would I pile my crap on in the garage???

a smaller, more rusted out POS?