Engine swap

[chevyt454]

I got my hands on an early 70's suburban 350. So out goes the 305. Just wondering if anyone thats done the swap before can give me a heads up on anything I may need to know. Thanks!

[Fast92RS]

Im in the process of doing the same thing. Everything is pretty much the same, such as accessories. The differenes come in to if your using EFI or going carb'ed.

[chevyt454]

I'm going carbed same as the 305. I was told I may have to change the cam due to higher revving of the manual tranny and a cowl hood for clearance. So to cut through the myths I thought I'd ask someone whos been through it already.
Thanks

[Fast92RS]

There will be no hood issues as long as you use the same intake or a similar one. I would get a cam that is compatable with the computer controlled carb you are using if your still using that style carb. If you still are using the computer carb your going to need to change the metering rods in it. GM had a 305 to 350 conversion kit for carbed camaros but it has been discontinued. www.gmcopo.com sell a few items such as the prom chip for the conversion.

[Tru2Chevy]

What are your plans for the 350 before you install it?

You mentioned a possible cam swap....what about carb and intake? Are you going to use the factory ones, or are you going to ditch the factory ECM and go for a standard carb and HEI setup?

- Justin

[chevyt454]

The 350 will be stock with Edelbrock 600 carb & intake. If I don't have to change the cam I won't. My buddy has this right now in his olds cutlass. He came across a 454 also out of a suburban & is giving me the 350 complete with carb & intake. The motor sounds damn good in the cutlass so I'll take it!

[BonzoHansen]

The first thing that comes to mind is 2-pc main vs. 1-pc main – if your 305 is the later 1-pc design, I think you need a new flywheel. Am I right on that? Are there any other items related to that?

[chevyt454]

I was told something about the bearings in the flywheel need to be changed. This will definitly be a learning experience! Thanks for the info.

[Fast92RS]

There is no bearing in the flywheel, except for the pilot bearing on the crank. You also have to keep in mind is the engine externally balanced or internal. That will make a difference in your flywheel choice as well. I personally would stick with the Computer Carb because I hate to hack up the wiring unless I was converting to EFI.

[BonzoHansen]

Does it need different muffler bearings too? :)

No way, if the engine is all set up and running well with that intake & E600, run it. CCC QJets are FTL.

[chevyt454]

Thanks! Thats what he said bearing on the crank. If I can help it she would have no mufflers at all! Just pipes coming out in front of the rear wheels! LOL

[Untamed]

Take the front clip off - don't try to swing the cherry picker and engine out of the bay without getting it as close as possible. Removing the clip can take up to 2 hours so plan on that for whatever time you have set aside for the day (or do it the night before).

Not sure what other words of wisdom you are looking for. General engine swap, or specific engine setup prior to the swap?

[Tru2Chevy]

Perfect time to work on small upgrades as well. Headers and a catback if you want and new motor mounts are a must. You could also take the time while the engine is out to inspect & clean the engine compartment.

- Justin

[chevyt454]

Just looking for past experience on similar engine swaps. This will be something to do during those boring winter months so I'm taking my time. Beer, pizza, buddies and tools in the garage!

[WildBillyT]

What are the numbers off of the heads? Some of the mid 70's trucks (yes, even light duty) used small valve/runner heads, which will hinder your performance.

And do NOT use a torker II manifold to try to save your stock hood. They are not the greatest.

[Tru2Chevy]

Pretty much anything larger than a Performer intake won't clear the stock hood (depending on what aircleaner you use). I have a 14" x 2 5/8" round aircleaner (offset to make room for the HEI) and it just hits the stock hood with a Performer intake and a Q-Jet. Not sure how the Holley 750 DP thats on there now will compare.

- Justin

[camaro2you]

if you need any help i know these thirdgens inside and out.

[chevyt454]

Thanks!

[johnjzjz]

after you get the motor i think you said its a 5 speed and in the crank center at the flywheel is a pilot bushing ( bearing ) as some call it you will need to install if its not their or the trans will make all kinds of noize with out it and yes the flywheel ( flex plate ) is diff you need a regular SBC wheel no offset weight like a 400 motor -- everything else will interchange except the nuts and bolts older motors and not metric -- jz