Passenger head by the oil fill neck. Drivers head by the pvc port.

243/799 heads


When did i say the lifter was good to 7k

 

Ok I just got really confused on this but I just read something that said that the l20 has cathedral port heads so idk what the heck. I thought they were they square port and the ls3 was cathedral. I know I can't use the heads but maybe the intake manifold?

 

When you find the cast number let us know, I'm curious to know what the 4.8s have stock now.

 

Ok so I just found this and now I can actually see the difference http://www.ls1gto.com/forums/showpos...22&postcount=7 so once again I cannot use the intake with the heads I have or the ones I want either. Ls3 are rectangle and 4.8 5.3 6.0 are cathedral as well as Ls2/6

 

I also found this it's kinda informative on the l20.
http://www.gmpowertrain.com/Powertra...IV%20Story.doc

 

sorry iamkeniff, i guess i misunderstood when you told OP "you already have good lifters." figgured that meant they would take some rpms...

 

Ok so they are 799 cast heads but the cast numbers are not where you said they would be but exactly opposite spots. drivers side is on the front of the head under the alltinator bracket and passenger side is at the back by the fire wall

 

Correct me if I'm wrong guys, but won't stock 799 heads feed a 4.8 all the air it will ever want N/A?

 

Does anyone know how much I can shave off the stock 799 heads to get higher compression

 

The prc 2.5 5.3 heads do not come in a 243/799 casting..... They are two different castings with, two different programs written for them to be cnc'd. The core charge is also higher for the 243/799 heads which is the reason for the 300 dollar higher price tag. If the OP wants cnc'd 243/799s he can go with the stage 2.5 cnc'd LS6 heads. Two totally different set of heads.