4.8 engine build question
 

will my flat top pistons work if i put in 5.3 crank and rods? tryin to build a torquer motor for a daily driver 4x4.

You can, and you'd have a 9.95:1 CR 5.3 liter(depending on heads). GM does it with an aluminum block and 799 heads, and calls it the L33 5.3HO.

NNBS trucks also use flat top pistons

Good deal, I was hoping they would. thanks for the replies.

Hmmm, I thought the compression height on the 4.8 piston was different because the rod length is different between the 4.8 and 5.3.

Nope.

Rod is different because the 4.8 crank has a shorter stroke.

Didn't TurboGibbs calculate a different compression height for them?

I've verified GM part numbers in the past, when I was researching this. The L33 piston part number is the same as the 4.8 liter piston.

Here's a pic of an L33 piston & rod above an older 4.8 piston & rod.
Attachment 137966

I'll have another LM7 apart soon, and I still have a set of 4.8 pistons here. I suppose I can take some measurements if that would make you a believer. :)

No, that's good enough evidence for me lol. thanks