Hi all, I currently have a 91 350 tpi in my bird. Now , I was thinking of swapping in a 400 cu inch chevy block. What would I need to do? I am willing to still use the stock tpi stuff as I am not concerned about making power over 4800 rpm's. Just want a fun stop light car. My questions are: In order to use my stock tpi manifold I would probably have to re use my stock 350 heads. Ok, but would I need to have my 350 heads drilled for steam holes? Also, what distributor should I use? How about a starter, can I re use my stock firebird starter? I am also assuming that I would have to use the flywheel and harmonic balancer that will come with the 400. Any help would be appreciated. Later

 

You can use your top end, steam drill the heads... it's pretty cheap to have done.
Use the TPI distributor. Your starter will only work if the flywheel has the same amount of teeth... actually if I recall correctly the 350 and 400 flywheels are balanced on the flywheel itself so they should be interchangeable.

 

You will need an externally balanced flywheel as was mentioned, however the L98 flywheel is NOT externally balanced.

Personally, I wouldn't be caught dead running an induction system that can barely feed a 305 on a 400.

 

You need a flexplate for 2-piece rear main seal, externally balanced. They are available.

Your 083 heads are much better than the 882's that came on the 400, but they would still benefit from basic port and bowl clean-up.

As a formerly-active TGO member often said, what you're proposing is "a lot a maze for very little cheese." Stock TPI will choke a 400 well below 4800 RPMs. Basically all of the TPI hardware will have to be replaced to give it a chance. You may lose some of the low end torque of TPI when you do that.

Maybe you should consider just improving your 350. Check the "Attilla's best builds" sticky for a combo that would befit your situation.