Sounds like you scored a sweet deal. If you are unfamiliar with small block 400 then you need to look into the crank to see if it is the stock unbalanced (ie externally balanced needing a special damper and flywheel or flexplate) or an aftermarket internally balanced crank. Did the heads have the small steam holes between each pair of cylinders to match the block?
You may also want to check the stroke since it was common to destroke a 400 with a 350 crank and special main bearing inserts (or a custom ground crank)
Last edited by Brods; November 26th, 2011 at 07:41 AM.