My buddy's 305 has developed a high rpm knock after he lost oil pressure one day...so we're looking for a 350 to swap in. A few basic questions here as far as interchangeability.

Will the 350 bolt to the 305 700-R4? I assume they're the same....

Will the 305 exhaust manifolds bolt to the 350?

And do the 305's and 350's share the same intake manifold designs, or are they different?

Thanks.....

 

The trans will bolt right up.

I believe the 350 had better flowing manifolds, double check that one, but the 305 ones will bolt up.

If it is tuned port, the intake is the same. If not, i am not sure.

If it is a tuned port swap, you will need bigger injectors for the 350 or it will starve for fuel.

 

Depends on the years of the two motors. Externally everything will bolt up but you may need to buy some parts if you are going from a 1 to a 2 peice rear seal. You can use the intake but you will have to modify the 4 center holes if you are going with a post 87 intake on pre 87 heads.

 

Thanks for the info guys. To add detail:

The 305 coming out is TBI.
The 350 going in, if he can find one, will be carbureted.

How can you tell if it's a 1 or 2 piece rear....I mean can you just look at the back of the motor and see if the seal is in 1 or 2 pieces?

 

Pre 86 was 2 piece seal. The TBI is a roller motor with 1 piece. I would look at a used L98 short or long block so that everything will bolt up.