Is there two different stock piston ring sizes for lt1's. According to this there is http://store03.prostores.com/servlet...95-5.7L/Detail

 

If you are sure your motor is stock it is 4.000...the size they are referring to is the ring thickness,not the bore size

 

Yes I know the bore is 4", but can you throw any thickness rings on any year lt1 as long as the rings are 4" bore?

 

The ring thicknesses have to match the ring grooves in the piston. Do you have stock pistons?

The Clevite part # is 41616 and the ring thicknesses are 2.0mm / 1.5mm / 4.0mm.

 

Yes they are stock pistons, so all lt1s are 2mm/1.5mm/4mm. This link shows 96-97 rings as 1.5mm/1.5mm/3mm http://cgi.ebay.com/ebaymotors/96-97...Q5fAccessories

 

If I'm reading the description correctly, it says there may be 2 different sizes used, and that you have to check your pistons. I've only seen the 2/1.5/4's, but then I don't know if I've ever seen the piston from a 96. The "Rebuilding the LT1" book shows the Clevite part # I listed. But he was rebuilding a motor that was coded as a 96, and has a vented Opti. But from the photo, and one of the captions, he cast doubt on the year of the engine since the timing cover doesn't have the CKP sensor.

Given the fact that your are basing your "I need new rings" theory on your uncle's "shake the piston" test, and MachinistOne has already debunked that theory, and you indicate it passed a leakdown test, are you even still looking for rings, and if so, why would you buy them before pulling the pistons? Buy them AFTER you pull the pistons so there is no doubt.

 

Yas I am getting ahead of myself, the pistons need to come out before I decide to buy rings. I also need rod bearings/bolts. What rod bearings and rod bolts should I use?

 

Take the engine apart carefully if thats what you're dead set on doing, use rod bolt condoms to keep from scratching the crank. Then take all those parts to a machine shop to be cleaned and measured. They will tell you if the block just needs a kiss hone at STD, or if it needs to be honed to the next oversize. They will tell you if the pistons are ok to be reused based off of ring lateral clearance and possible skirt collapse or scoring. The crank will be measured to determine if it needs to be ground 10/10 or if it can be simply polished. The rods will be checked for size to see if they need to be clipped and honed. All these steps to assess the condition of your parts will determine what bearings, rings, and possibly pistons you will need to put the motor back together.

They should be able to supply you with all the right parts the first time around, make sure they're familiar with the LT1 engines - the cranks are cut differently than standard one piece rear main cranks so it cannot be simply swapped out with an already ground and ready to install crank without a balance job first.