Ring job or replace

I have a 1990 GMC Sierra K2500 with a 5.7 Mr. Goodwrench engine. #3 cylinder is pumping oil. About a quart every 50-60 miles. I'm not a mechanic but I can only think of two reasonable options, #1 Pull head replace rings, #2 replace with a used moter. Which is the most cost effective? Or are there other options. I'm a shade tree mechanic ( very little mechanical knowledge. I've replaced starters, radiators,window motors and that's about it).

Thanks

TJ

Smartest thing is to find out where the oil is coming from.
It may be something as simple as a split valve stem seal.

Do a compression check, its an easy decision maker.

a used motor would be easier. if you do put in a used replace the rear oil seal before installing it. if you do have a bad valve seal it's an easy fix. i agree with herefordman compression tells all

Just wondering if anybody has any info on how low it can go... Compression that is. I have a 95 sierra 4x4 1500 5.7 tbi. When I ran a compression check ( to figure out a loping problem) I found that all 8 are between 128-140.. The engine uses no oil and has great power. The body is super with no rust ( New England Miracle) I'm hoping to get many more years out of it.
I think that I have solved the loping problem thanks to this site. It was skipping/hesitating just off idle 1100-1500 rpms I finally just plugged the egr line and it seems to have taken care of it. After Fuel pump, filter, tps, MAP, Plugs, Wires, Cap, Rotor, Junkyard TBI..... Wish I had found this site earlier... Anybody need a Good TBI???

I guess I'll just need a new EGR unless it turns out to be the actuator, can they be checked? I tried Vacuum on the EGR with my handheld vacuum pump, it seems to take some vacuum and then bleed off slowly, I then looked at some new egr's online and one had a note next to it " can not test with vacuum" WTF? How can I be sure mine is or isn't bad??


Thanks for the help and sorry for the rambling..
CHris