Jump to content

FirebirdNation.com is the premier Pontiac Firebird forum on the internet. Supporting Members do not see the above ads.
- - - - -

301 Swap To 400

  • Please log in to reply
No replies to this topic

#1 oragonads


    Firebird Newbie

  • New Member
  • Pip
  • 2 posts
  • First Name:Cliff
  • Year: 1979
  • Make: Pontiac
  • Model: Firebird
  • Engine: N/A
  • Transmission: N/A

Posted 05 June 2009 - 10:46 PM

Hey, I have a 1979 Firebird that unfortunatley has a seized 301 so I'm planning on putting a rebuilt 400 out of a 1978 Trans Am. I used to have a 1973 Camaro which I had to sell due to financial situations at the time. I never dealt with anything Pontiac (always had Chevy's) and didn't know anything about them until the information I have been researching lately, and didn't know the differences between the two.

I have since learned that Pontiac has no big block and small block, but they are the same size except the 265 and 301 which suck anyway.

From what I have been able to find I'm under the impression that the 301 to 400 swap will be pretty easy. The 301 engine mounts are the same as the 400 so there shouldn't be a problem there.

One thing I'm not yet sure about is if Firebirds have different front coil spring sizes for the larger engines such as how Camaros have small block springs and big block springs. Since Pontiac blocks are all pretty much the same I'm guessing that the springs are the same unless the 301 springs are different because the engine is lighter?

I also know I have to get some exhaust manifolds or headers for the 400 because the 301's don't swap over. One question I have is if the exhaust will bolt up to both exhaust manifolds the same or not?

I have also heard that the HEI distributor will also work in the 400 but i will have to recurve it. Is this true, and if so how do I go about recurving it?

Thats pretty much all I can think of right now. I'm also assuming there wont be any fitment issues with the 400?

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users