400 small block ?
 

hey guys have a 400 small block chevy ?..... a buddy @ work bought one complete to build into a street strip engine. question if he puts Dart sportsman II heads on it will he have to drill steam hole in them?? somebody told him he had to & I just don't know? Thanks Greg

novamoation

Yes, he does have to dril the steam holes. I would rather build a 383 based on a 350 block. The 400 blocks are known to crack in the valley area when you strat to make power wtih the OEM block. Seen this happen several times.

They are not necessary, and many aftermarket heads don't even have water jackets where you would need to drill into them.

Now if you were building the engine for a tow truck or van, or an endurance racing application you'd rather have the steam holes, but with a proper cooling system, it would never be an issue.

"Despite the high cost of living, it remains popular"
Dave Cook
C375