I used a northstar preformance stud kit on my '98 Seville STS and it has coolant coming out of the tail pipe again. It's from the rear bank. The heads were straight and rebuilt and the block was straight. When it first started it was missing on one cylinder and had water in the intake. I pulled the intake tube off and there was water running out of the maf! There was white foam under the oil cap and pvc valve too. After running for a while it got better. It stopped missing, no more foam under the oil cap or pvc valve, and the steam coming out of the exhaust had reduced but not stopped completely. It doesn't get hot, the highest it got was 3/4. I put a bottle of bars stop leak, the one you don't have to flush the system first, and it just barely has steam coming out of the exhaust now. But I'm not sure if it was the stop leak or the motor going through a few heat cycles helped? I did have to tap the heck out of the heads to get them on the pin studs so I'm thinking maybe I damaged the gasket? But the front head was just as hard to get all the way down and it's fine. It runs great and idles very smoothly. And because it has gotten progressively better I'm wondering if it'll keep getting better on it's own? I would just drive it and see but I bought the car with the blown head gaskets and the tags were very expired so the total cost to register is over $650 and it'll need a smog too. Plus it has no plates. So all this was happening in my garage at idle or reving between 2000-2500 rpms to get the temp up. Before I called it a night I did drive it through the streets around my house and I did three first to second wot runs and it pulled hard all the way to the redline. Like I said I bought it with the bad head gaskets and only drove it off the tow truck in front of my house and into my garage and I was very pleased with how hard it pulls all the way to 6500. Especially with 98000 miles on the bottom end. And I was very happy to finally get to drive it!! I'm just wondering if anyone has had a similar situation with coolant still coming out of the exhaust after a stud kit install or anyother head gasket repair? I was thinking of taking the valve cover off and torquing the nuts on the head studs another 10lbs? I'd appreciate any advice thanks!