LS1 head castings

[surgitech74]

Can anyone tell me if heads with a casting # of 799 will directly replace heads with a #241 casting?

[BerryWS6]

Yes, I have a truck with those heads and they came on HO 5.3L trucks, I dont know about the vavle size, the trucks normally have smaller vavles

[9T8W66]

Like said above they'll bolt on but the truck heads have smaller valves and a smaller combustion chamber.

[surgitech74]

What will that do for my performance?

[Zoilus]

My LS6 Stage 2.5 heads from Texas Speed and Performance, are 799's. they are great performers and I still need to get my car properly tuned.
Check the link:

[BerryWS6]

My LS6 Stage 2.5 heads from Texas Speed and Performance, are 799's. they are great performers and I still need to get my car properly tuned.
Check the link:

yea they're supposed to be just like the LS6 except with smaller vavles from GM but you have a port and vavle work then there would be no difference