I've got a short block in front of me and don't know if it is a 4.8 or 5.3. I need to know before I install the cam. The cam is in hand and ready! Can any please tell me what the bore size is of a 5.3 liter, or where I can look it up to find it?
Any info would progress the next cam motor on LS1tech,
thanks guys

 

the bore size is 3.78 on both the 4.8 and 5.3

 

How can I tell the difference in the two?

 

the site i found was www.mortec.com. im sure there is a better one out there though.

the only other thing i can tell is the crankshaft casting number on the 5.3 which is 12552216

 

It should be stamped on the block somewhere 5.3 or 4.8

You could messure the strock though by measuring how far down the piston is.

http://autos.msn.com/research/vip/sp...IP&tab=2&sub=1

The engine specs you want are the 3rd to the last chart from the bottom.

 

it has both

 

Its the same block for both motors.

Pull a spark plug and look at the pistons. The 5.3 will have a dish and the 4.8 will be completely flat on top.

 

The piston travel spells 4.8 all the way!
When I take this motor back how can I be sure not to get screwed again?
I hope taking the plug out will tell, going out to pull plug out of my blown motor now!

 

I'm sure someone on here knows the stroke on a 5.3? I hadn't noticed dish pistons on a 5.3 block, I'm pretty sure I have info on it at the office.

 

I'm about 99% sure at this point that the engine is a 4.8, going to check some numbers at the dealerships first thing in the morning. Not really expecting to find anything out though. Feel sorry for whoever buys the engine I've gotta take back!

Jim I'll be giving you a call in the morning about seeing if you mind again letting me get your 5.3 heads checked out since mine are going to have to go back with the engine.

Does anyone have any suggestions on how to make sure I'm bringing home a 5.3 this time? Best suggestion so far is looking for dome shaped pistons, which are going to be hard to see through the little spark plug hole, if 5.3 even have dome pistons. Can anyone else verify this?

The engine out there whatever it may be strokes out at about 3.2 and has flat pistons. Are there any numbers I can reference with the parts department at the dealership tomorrow?

Please help me out guys, my blown motor is barley limping along!