Can you guys tell me if the 4.8 and the 5.3 blocks are the same, as in bore if so im gussing that the ony diffrence is the heads etc... My question is if i wanted to build a 5.3 could i use a 4.8 block without boring it over?

 

I think the difference is just the rotation assembly, crank, rods, and pistons.

 

Yeah, I agree...the heads are the same, I'm pretty sure. The 5.3 uses flat-head pistons with longer con-rods.

 

its the 4.8 that has the flat top pistons, the 5.3's are dished. the 5.3 shares the crank and rods of the 6.0 and 5.7 i think...dimensionally at least. there are some differences in the cranks with oiling and stuff.