Classkilla

It's time to build a new motor. Current set up is a bbc 474.
Looking to step into the new century. My class rules state no power adders, no fuel injection and not to exceed 474ci. Class currently doesn't allow for aluminum heads. So I need 474ci iron head and plenty of HP.. Please fire away with suggestions..

baronsmith98

iTrader: (2)

How much power does your 474 make?

zraffz

iTrader: (1)

Just throwing this out there without knowing if it's 100% true but when you get into those cubic inches, I'd imagine a head that is physically larger (big block) could significantly outflow a ported GM cast iron truck head.

The stunningman

iTrader: (47)

Agreed with the guy above this is not a class for a LS engine as the only cast iron heads for a LS (to my knowledge) were the very early 6.0 cathedral type which will limit hp significantly on any big CID engine.

BBC have plenty of good offerings. You need help refining your BBC not a move to LS.

baronsmith98

iTrader: (2)

Sorry see the aluminum head part.

JoeNova

Yeah that iron head part kind of screws it.
There was only a single iron casting ever offered for the LS in 1999-early 2000 and it wasn't a good one.

The class seems like its geared more towards being a nostalgia class.

Classkilla

Yes their excuse is they want to keep it competitive and cost effective to build.

Classkilla

Never been on a dyno. Estimates are 750+

zraffz

iTrader: (1)

Well if I were you, I'd stick with a big block. You will not get that out of early truck heads.

Guys push 700+ HP out of properly set up pump gas 496 motors. I bet you can get over 800 HP.

Classkilla

I'm being told my estimate was rather lite builder thinks we're 850ish.
So what is a realistic number for a lsx in the 474 ci range? No turbos or nitrous with a good set of heads.

JoeNova

Similar to a comparable big block, but at the weight of a small block.

If you're forced to run carb, iron heads, etc, it would be better to stay with the big block.