94-6spd

I am trying to figure out the engine that I bought. It's either a 4.8 or 5.3. I was told that the 4.8's had dished pistons and the 5.3's were flat tops. Is this correct?

Zick

iTrader: (18)

My 03' 5.3 did not have flat tops. There is a small dish to them.

thunder550

iTrader: (70)

If I remember correctly the 4.8's have flat tops and the 5.3's are dished. The stroke of the 4.8 is shorter, so the flat top pistons help keep the CR up. Both engines are 9.4:1 CR, and the bore is the same.

thunder550

iTrader: (70)

From Handzel's book:

LR4 - 4.8 - 3.267" stroke
LM7 - 5.3 - 3.662" stroke

Both have 3.779" bore

LR4 is 9.47:1 CR
LM7 is 9.49:1

The book doesn't have any details on the pistons, but with the shorter stroke, the 4.8 has to have the flat pistons to keep the CR up.

94-6spd

Thanks guys. That answers my question. Where can I find info on interchangable parts such as cranks and pistons from the other LS engines. How far can the 4.8 be bored?