I may be getting some 5.7 heads and I was wondering if anyone knew someone in the houston area who can p&p them?

 

Would you be opposed to sending them out?

I know llyod elliot does decent work cheap somewhere in texas.

 

maybe if I cant find anything close for cheap

 

When it comes to making your car fast, especailly NA, heads are a GREAT place to blow your money. I would be very reluctant to get mediocre head work over $300 difference.

Better heads mean you can run less cam and make more power. They also mean you can run a bigger cam and make a lot more power. When you have crappy heads, you try to make up for it with cam. Its really hard to do this if they dont move air well so you are really spending a lot of cam to make up for heads. The point of dimishing returns with a cam is much lower with crappy heads.

Look at an LS6 vs an old small block. Those guys are shaking with average/crappy heads just to make power that an LS6 can make with a baby cam. And they can add more and more cam and not gain at nearly the rate an LS6 would.

when it comes to LSx style heads and a street car; its hard to go wrong with anyone halfway reputable. I just wouldn't let a backyard monkey hack away at them. Most of those kinds of guys dont understand airflow and bascially copy other peoples work or try to hog them out. Then they'll do stupid stuff like "get it to tumble." (but prevent terbulence?)

 

I was under the impression 4.8/5.3 heads were better than the LS1 heads...

Yes, you can have the best heads and a **** cam and still make great power. But you can have **** heads and a great cam and make no power.

Aside from that, other supporting mods will make a good difference on top of head work.

 

better in the sense that they have smaller chambers for higher compression in an LS1. Other than that, almost identical. And LS1 head would yeild some really low compression.

supporting mods are important as well. If you can budget money (or time yourself if you are capable and know how; i sure as hell dont know enough but have friends that do so look into that), custom headers will REALLY help your motor shine. The more I research it, the more I realize the importance of exhuast scavaging. I really hope to fab up my own custom headers one day when I am set on a setup. The silverado should give me a great place to learn since it has little packaging issues. Most sports car's packaging really skrew things up. I've watched Roush engine builders do it so I know how (it took him 30+ hrs to TACK a set of turbo headers!, probobly another 30 just to weld them). That could be a REALLY cool project for someone with limited money but with a welder and time.

Does anyone know how to "how" to custom tune headers? I know you need to concider your powerband, exhuast velocity and the speed of sound plays a factor as well. If you go with unequal length, shouldn't you have the pulses be the closest at the RPM you want power to peak at? something like that? how does speed of sound play into all of this if at all?

 

Well the intake valving is different also. The 4.8/5.3 use that 1.89" due to the smaller 3.78" bore on the truck motors. Intake valve sizing is of high debate here but I'd go no larger than a 1.94" on the intake with that small bore.