383 vs. 400

[93blackthunder]

I recently came across a 400 block for $250 i was wanting to run a 383 but wanted to get some input on which would be better or are they pretty close? Just looking for a little info on running a 400 like if anything special is needed or other pros and cons to each. thanks guys for you comments in advance.

 

[Horns]

The 400 is a good block, it's just a different beast then the other small blocks. The 400 is externally balanced and has steam ports through the block and heads to name a few.

 

[93blackthunder]

Will vortec heads fit them? And different beast as in good?

 

[Horns]

Different beast as in you have to know the differences because you'll build it differently. Vortec heads will work but you'll have to machine the steam ports into the heads.

 

[SAATR]

Caveat Emptor! 400's have been out of production for several decades now, so be sure to measure the bore before you buy. Getting nearly impossible to find virgin blocks, and difficult to get one that hasn't been bored .030" plus. Wouldn't want you to get stuck with an engine that's on the verge of being unusable. That said, if it does need a rebuild I would go with a 5.7" or longer rod to help out the rod ratio. Steam holes are a must with any head you use, and be sure to have plenty of cooling capacity as these motors don't cool as well as the other smallblocks due to the siamesed bores. Thin cylinder walls will only exacerbate this, so thicker is better.