mlevario99

I got an engine/tranny combo from a friend, he got the engine/tranny from a wreck truck, I dont have the vin number. I am trying to find out what what size engine I have, a 4.8 or 5.3. The engine came from a 2000 Silverado. The engine block has this number on it 12551358 and in the side of thge block it has a 4.8/5.3 stamp on it. How do I know what engine size I have, I research the 125513548 casting number, but it just tells me that I could be a 4.38 or 5.3.

Thanks

cutlass_455

iTrader: (2)

Whats the casting # on the heads?? Should be a 3 digit #.

mlevario99

the casting number on the heads is 862.

Thanks for your help

71ANTICARB

iTrader: (23)

Those heads came on both. The only ways I know personally is that the 4.8l has flat top pistons and has a different crank.

71ANTICARB

iTrader: (23)

Just found this look at the last post.

https://ls1tech.com/forums/conversio...ification.html

trav-tech

iTrader: (1)

Pull a spark pug out and shine a flash light in the hole turn the crank till you can see the piston top if it has a dish its a 5.3L if its flat top its a 4.8L

firstgenguy

iTrader: (6)

anyone have pictures of the two different pistons? I just pulled my heads.

Bo185

You will know the 4.8l will be completely flat and the 5.3L will have a little dish in it.

5.3L pistons

firstgenguy

iTrader: (6)

Bo185 I can't see your pic but here is what I have. It's a 2001 block.

eviltwin_1987

iTrader: (18)

That's a 5.3

deuce4935

iTrader: (2)

^That would be a dished piston from a 5.3 or LQ4, LQ9 and 4.8's had flat tops.

firstgenguy

iTrader: (6)

yeah that what I think confusses some people cause there is not much of a "dish".

mlevario99

The pistons have the dish so it is a 5.3. I have another question, the following picture shows the flywheel, my question is, do I need to replace it, or I can still use it, two of the three holes are a bit rough, is that normal. Thanks

ShortChevy

iTrader: (21)

I would replace that

SSjon

iTrader: (4)

It looks like someone cut them out for some sorta conversion to the older style torque converter

Chris10an

iTrader: (1)

OK is the 4,8 and 5,3 piston the same hight, so we can use the 4,8 piston to rise the comp on a 5,3L?

Bilster

iTrader: (21)

That's correct. The two pistons share the same compression height.It's a fairly popular swap.

mlevario99

ok, I am going to replace it. Are the flywheels the same for all 5.3, I believe the truck that this engine came from is a 2000 chevy silverado 2wd.

Bilster, what are the advantages of swaping the pistons form a 4.8 into a 5.3 engine.

Thanks for all your help.

ls1okie

Flywheel differs from the 4L60E to the 4l80E. The difference being the flywheel for the 80 will have the spacer for the converter. Advantage to piston swap is you will have a higher compresion 5.3., will only be around 15 hp at the flywheel.