Rpayne41985

iTrader: (12)

I have a set of pistons out of a newer aluminum block 5.3 that I want to put in my 04 iron block 5.3 both blocks had the floating rods just wondering if they will work. I remember reading somewhere that the aluminum 5.3 had a different deck height

cobalt964

I have installed the 4.8/5.3 flat tops into a 5.3 iron block with no issues.

Rpayne41985

iTrader: (12)

Anybody else have any input

Rpayne41985

iTrader: (12)

Should I have it rebalanced

A.R. Shale Targa

iTrader: (2)

Easy enough to just weigh each of the two different pistons and if the difference is less than say 10 grams then it probably won't matter. The GM balancing used to be around 30 grams on GEN I stuff; LS might be a little better but doubtful that it's less than 5g like a performance shop would do.

MustangLS

iTrader: (5)

I swapped out my 04' gen 3 rods/pistons (i lifted ring lands on 2 pistons on a nitrous backfire) for a set of gen 4 rods/flat top pistons. They were taller than the deck surface by .003 to .005 (approximately) if I remember right. Weight difference was 35 grams and I decided to chance it and not re-balance. I don't have many miles on it yet just been running it to work on the tune and a few pulls to 5k but everything feels good so far.

Rpayne41985

iTrader: (12)

Yeah I thought they were a bit taller just couldn't remember for sure

1FastBrick

iTrader: (16)

There is no difference in deck height between the iron and aluminum 5.3L blocks. Factory deck height should be around 9.240

The 4.8L and 5.3L pistons have the same pin height.

The difference being that the 4.8 piston is a flat top and the 5.3 has a -8cc dish.

The L33 is the exception being the only 5.3L that received flat top pistons from the factory in an aluminum block.

cobalt964

Gen 4 pistons are flat tops but the deck height is the same as in a gen 3, and the piston pin height is the same as a gen 3. but don't try to run 4.8 rods in your 5.3 as the piston will stick out of the hole.