pretty much what the title says. a buddy of mine bought a 99 gmc with the 4.8 and hes was wanting to do some up grading. i hopfully will be getting new set of heads and cam for my ls1. so pretty much wondering if my heads and cam will work on his block and if so, what type of gains can he expect? the only thing i can think of that might keep this from working would be the valve lining up in the cyl. truck is just a 1/2 ton z71 with dual exhaust. nothing special.

 

Nothing

 

https://ls1tech.com/forums/general-l...eads-5-3l.html

I thought 4.8 and 5.3 both used the 706 head but I am not 100% sure