Trying to order rings for my 502's and I guess there are a few different options on thickness. Any ideas with stock pistons. Also going to replace the oil pumps for safe measure, what oil pumps does everyone like to run. Brand? high pressure/standard, standard volume/ high volume etc. Thanks in advance.

on the stock 502's there is only 1 option on the rings. Grab a set of the metric stock rings http://www.cpperformance.com/p-14377...ric-rings.aspx

I always run a high volume Melling pump, but that is just me.

+1 on rings
I always had somewhat low oil pressure on my 502, but when I rebuilt it I installing Mellings HV 10778 and it is much better.

the std ring pak uses a very light tension oil ring and the 502s end up with oil in the combustion chambers because of it. total seal makes a very nice set of rings for the stock pistons that fix this. if you are rebuilding the stock motor with stock bearings and stock clearences, then there is no benefit what so ever to the HV pump . in fact it will sap power and make extra oil temp because it will force the bypasses open all the time. the stock pump on that motor in, esentially, stock trim is the correct answer on that motor.

Thanks for the help guys. I ordered two sets of total seal rings.