i just got LQ4 6.0L but i found out it has cast Iron heds
now i need to know the cast iron vs aluminum ? which is better ? should i stay with what i've got or get an aluminum set of heads ?
PLZ HELP ME !!!!

 

if its gonna be N/A I would deffinately look for a set of alum heads cause they are heavy like a ****. if its gonna be forced induction you may wanna keep the iron heads just for the fact that it would be hard as hell to blow a head gasket.

 

... dump the iron heads you will be able to screw in more timing (power) with aluminum... aluminum counterparts are available cheap on ebay and popular forums... just look around.

Iron heads are pretty rare considering... maybe turn them over and make an ash tray out them... good conversation pieces

Bill

 

iron heads are old news, go with aluminum

 

AL heads will dissipate heat much better than Iron. Whether ur doing forced induction or not heat destroys HPs. Its definately more of an issue if u plan for a supercharger tho. R/

 

If you got a LQ4 with iron heads, it must be a 99-00 LQ4. These have fitment issues and won't bolt up like the 2001+ LQ4 blocks. I think its something to do with the crank or something. Check around and make sure it will fit first. What's it going in?

 

Yeah the crank is different on the flywheel end....it is too long because it was designed for use with the 4L80. You can swap to a newer crank though.

 

I always thought Heat=Horsepower....

 

To a point maybe, but was taught that heat robs...thats why an intercooled and meth injected SC runs greater HPs. Also why running high IAT's will rob power. I'm definately not an expert, but heat steals power. My radix runs a heck of a lot more power in cooler ambient air temps and IATs.

 

But IATs are a separate entity in itself. I thought that cooler air going into the motor causes the fuel to atomize better thus creating a hotter charge(able to be combusted hotter) as the spark plug fires. I have always been taught that the hotter the combustion chamber, the more hp. I was once told that despite popular thought, a cast iron head will produce more hp because it was less of a conductor than Al and held heat around the combustion chamber. I was a bit confused by this but it kinda made sense.