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engine combo recomendations

I have a factory production 400 small block chevy bored 0.60 over.I've noticed in the popular hot rod magazines that alot of guys don't run a block of this displacement.To be on the honest side,Im trying to exeed horsepower numbers of @ least of 580-610 on motor w/o nos.
 

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Goldmouth85 said:
I have a factory production 400 small block chevy bored 0.60 over.I've noticed in the popular hot rod magazines that alot of guys don't run a block of this displacement.To be on the honest side,Im trying to exeed horsepower numbers of @ least of 580-610 on motor w/o nos.
A 0.060" overbore on any small block Chevy is at or over the limit of overboring for a production block such as you have. When the cylinder walls get too thin, there is insufficient mass to quell vibrations set up by the piston rings which are then transferred to the water jacket side of the wall and allow the formation of air bubbles out of the coolant water. These air bubbles cling to the cylinder wall on the coolant side and prevent cooling water from getting to the wall to carry away heat. Result, an overheating motor.

At 600 hp, I think you're asking too much from a production block. There is insufficient structural integrity in the casting to stand up to this much abuse. The main caps will begin walking around and pretty soon, the whole shebang goes south due to oil being wiped off the bearing surfaces. Either that, or the crank will pull the webbing out of the crankcase and you'll run over the crank or main caps will break with the same result. And that's assuming the crank or rods don't break first.

It is possible that you could make 600 hp for a little while with a naturally aspirated 412, but you'd have to use a pretty healthy static compression ratio, a lot of cam and some real good heads. I wouldn't want to make any bets on how long it would last.
 
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