i currently have an '87 305 tpi motor and i'm going to be building a 355 tpi motor and was wondering what parts i can safely swap from the 305 to the 350? i'm going to be using the crank from the 305 and having it cleaned up and balanced properly to save some cash, but what else could i swap? the 305 only has 49k miles on it so... the parts are good. can i swap the distributor? i'm going to be using the whole tpi unit with some changes here and there. i'm buying new sportsman 2's for the heads and goign twith a lt4 hotcam. can i use the same roller lifters? any other info would be helpful, thanks a lot!

 

can a 305 crank be balanced to be a 350 crank? wouldn't they have to add weight to it since 350 pistons are bigger? Probably easier to get a 350 crank.

 

yeah they balance it and clean it up so that it won't wobble around in the engine. its a lot less cheaper than buying a 350 crank. the 305 is plenty strong enough.

 

im kinda in the same boat but im going to be swapping carb 305 to carb 350. im guessing the alt starter distributer... just about all that is swappable.

 

yeah, thats what i'm planning to use except tpi on my motor. i don't know if the water pumps are similar but mine is going on my engine now anyway so gotta go new on that.

 

You could buy a reground 350 crank & new bearings for less than rebalancing the 305 crank is going to cost you. If it is already in the 350 you're going to buy to rebuild, it isn't even a contest.

The engines are basically the same, assuming you get a '87-later 350. You can reuse your lifters. Water pumps are the same on either. You should port the plenum and base for better flow, aftermarket runners are always a good idea. AFPR, perhaps even 22# injectors.

The exhaust chokes a 305. You were planning on upgrading that, correct?

 

Last year I bought a reground 350 crank & bearing kit for $160, that has got to be cheaper than the machine work to properly convert a 305 crank. Don't cheap out on the lower end, especially if you are building more power, you will pay for it in the long run.