I building a forgen LS1 and i have 873 iron heads witch flow the same as 317 heads. My concern is putting iron heads on aluminum block and the motor being boosted. I know the that iron head don't dissipate heat as fast as aluminum heads. So what do you guys thunk?

Casting Number 873
Head: 1999-2000 LQ4 6.0 Liter Truck
Material: ***Cast Iron***
Part Number:
12561873
Combustion Chamber Volume: 71.06cc
Compression Ratio: 9.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

 

I would start looking for some 317's. I see them going for $300 all day long...

 

im not an expert by any means but to my understanding the aluminum heads will also help prevent detonation which is a big reason to run them especially with a boosted motor unless ur just building a really budget build that will have a spot on tune.

 

you have an ls with iron heads?

 

Iron heads are not a good friend of boost. A full Iron set up does not make any sense weight wise. Even then you see a lot of guys running an Iron block with Aluminum heads. This is because heat retain ability of iron compared to aluminum is much greater (about 10X more) making detonation a big issue in the combustion chamber. Do what you must but that set up is not looking good.

 

I would go ahead and try to find a set of aluminums if you have some extra budget $$.

Aluminum heads can take almost a full point more compression and be fine on pump gas, which means in your case (F.I.) that it can handle more boost before detonation leading to catastrophic failure.

Good luck