they would have different part numbers more than likely. i knew i was saying a part wrong. the stroke is different on them right?

 

They would have a diff part # even if they were identical? Is that what you're saying? Yes, the stroke is diff., bore is simmilar.

 

it wouldnt suprise me since it is 2 different engines. thats just how they do it sometimes. also the year model can change the part number also. ive worked at a ford dealer and now i work at a dodge dealer in parts and they do some dumb things with part numbers

 

4.8L=5.3L bore
5.3L=5.7L=6.0L stroke

 

i think all you have to change is the crank. the difference in the pistons are a 4.8 is flat top and the 5.3 has a slight dome therefore, giving the the same comp. i was thinking of putting a 5.3 crank in my truck also, the comp will be higher though. i work at the local chevy dealership and i will check this out and let yall know for sure

 

if you only did the crank the pistons would hit the heads. you have to use the shorter 5.3L rods also.

 

"i work at the local chevy dealership and i will check this out and let yall know for sure"

That would be great. I'll look forward to hearing what you have to say.

 

ok the 4.8 has a shorter stroke and longer rod than the 5.3 which has a longer stroke shorter rod but the 4.8 pistons are flat top and the 5.3 pistons are dished not domed. if you want you can put in a 5.3 crank with the 5.3 rods and stock 4.8 pistons but it is going to raise the compression up how much dunno. but if you do so i would check the clearances between the heads and the pistons just to be safe. and do a good tune and 93 octane fuel. heads are same all manifolds are the same hell even the block is the same just diff rorating assembaly.

THIS agrees with everything i said except the fact of the rods it says on the chart the 4.8 rods are the same as the 5.3 rods but that makes no sence unless the 5.3 piston it REALLY short

 

Well, one of the sources of info is obviously wrong. ???

 

i also work for a chevy dealer.