Engine overhauled with 6.2L parts and this vehicle has a 5.3L

The lifters for a 6.2 and a 5.3 are the same part. The rod and main bearings are also the same parts for both engines. If it runs fine and has good oil pressure I would do nothing as they are the same parts in both engines.

L83 (the 5.3) has a bore of 96.01mm (3.779 inches ) and stroke of 92mm (3.62 inches).

L86 (the 6.2) has a bore of 103.25mm (4.064 inches) and stroke of 92mm (3.62 inches). So.L86 is a bored L83 in a sense. Therefore, the rings are different.

The standard oil pumps are the same. It depends on the aftermarket manufacturer, but high volume or high pressure pumps may be different.

Glenn

The rings are different and there is no way they would interchange. As Glenn said the 6.2 is basically the bored out version of the 5.3 so the oil pump and many other parts will fit both.
There is no way that 5.3 rings could be installed on the 6.2 pistons so I would bet that there is some for of miscommunication going on if the claim is that they used 5.3 rings.

You're welcome, I would probably ask them to write down or at least verify whet they were saying. I could see them getting a kit for the 5.3 and using the parts and just swapping out the 6.2 parts as needed, it may be that a 5.3 kit was on sale or they had one on hand. With all of the mess that's going on these days they may have just taken what was available. That way you would know what you had and not needed to worry. But as I said above, if it's running good and not using oil or other problems I wouldn't worry much.

I agree. But you absolutely "must" find out what rings were used! The 5.3 rings will fit on a 6.2 piston, but there would be at least a 30 thousandths ring gap and that is unacceptably excessive, and noticeable. 4 thousandths per inch bore gap is the acceptable industry maximum (and some is absolutely needed for ring heat expansion), so about 16 thousandths would be your maximum. 5.3 rings would be twice that from the get go.

There is no way that if you had a 5.3 to use 6.2 rings. The pistons could never fit back in because the rings would never compress enough to slide the pistons back into the cylinders.

I won't say the 5.3 rings won't work - at least in the short term. But if they were used, I would anticipate excessive engine blowby, lowered compression, higher fuel usage, higher oil usage, and lowered performance later on with their use as wear increases their gap even more.

It is not my intent to scare you, but to give you information to relay to your engine rebuilder that you know what you are talking about. Ask for their invoice for your rings. They should be happy to show you if they used the correct parts. I truly hope they did.

Glenn