HomeHome  PortalPortal  CalendarCalendar  GalleryGallery  FAQFAQ  SearchSearch  RegisterRegister  Log in  

Share
 

 305 to 350 swap

Go down 
AuthorMessage
Norm

Norm

Posts : 48
Join date : 2019-06-21
Location : Central Washington

305 to 350 swap Empty
PostSubject: 305 to 350 swap   305 to 350 swap Icon_minitimeMon Jul 08, 2019 2:36 pm

I was looking at buying a 92 Caprice with a 305 in it that has 225k miles. So naturally I’m thinking an engine swap might be a good idea. What would it take to swap it with a 350? Can I reuse parts off the 305 if I were to get a 350 long block from Summit?
Back to top Go down
81X11

81X11

Posts : 9876
Join date : 2010-06-23
Age : 45
Location : Round Rock Texas

305 to 350 swap Empty
PostSubject: Re: 305 to 350 swap   305 to 350 swap Icon_minitimeMon Jul 08, 2019 4:06 pm

Norm wrote:
I was looking at buying a 92 Caprice with a 305 in it that has 225k miles. So naturally I’m thinking an engine swap might be a good idea. What would it take to swap it with a 350? Can I reuse parts off the 305 if I were to get a 350 long block from Summit?

You just need a 350 computer I believe. Plugs in. I have read some folks say the throttle body is different, but will let other comment on that. For now I'd look for a 92-93 Caprice/Customer Cruiser/Roadmaster computer.
Back to top Go down
Fred Kiehl

Fred Kiehl

Posts : 5199
Join date : 2009-11-13
Age : 70
Location : Largo, FL 33774

305 to 350 swap Empty
PostSubject: Re: 305 to 350 swap   305 to 350 swap Icon_minitimeMon Jul 08, 2019 11:55 pm

The 93 computer has a better fuel curve, and the 350 needs a computer from a 350. It may also need the spark control module on the relay bracket. You can use a lot of the parts from the 305 on the 350. One difference is the starter, the one for the 305 has a short bolt on one side, and the one for the 350 has the same size bolts on both sides. 

As far as using a long block, make sure the long block is a one piece rear main seal type. The TBIs are the same. You need to use a similar camshaft as the stock one to use the stock computer. If you choose a different cam, you will require a specifically burned chip. If you can get the cam and computer from a 93 9C1, it will make 25 more HP than the stock LO5, but you need the 9C1 Y pipe, or put duals on it. I have written the instructions for duals on this forum a couple of times, but I do not know where they are, so you will have to search for them. Putting an over the axle pipe on the driver's side is tight at the gas tank, and the tank needs to be insulated from the pipe as well.

If you are going to get a long block, you might consider a Vortec long block, with the GM intake for the TBI. You can also get 46mm TBIs that will flow more air. You must then port the intake to the size of the larger TBI for it to work properly. You need a new chip, and an LTZ or 9C1 computer would be a nice addition, but not necessary. If you go this way, you need the Felpro 98000 intake manifold gasket set. If you have more questions, let me know.
Back to top Go down
Sponsored content




305 to 350 swap Empty
PostSubject: Re: 305 to 350 swap   305 to 350 swap Icon_minitime

Back to top Go down
 
305 to 350 swap
Back to top 
Page 1 of 1
 Similar topics
-
» Swap profile to left hand side

Permissions in this forum:You cannot reply to topics in this forum
GM Longroof Forum :: Longroof Tech :: Engine-
Jump to: