Hello, I'm new to your site and was wondering if some kind soul could give me some good advice. I have a 1972 Skylark Custom Convertible. I picked up a 1973 455 and did a complete rebuild. I bought one of the TA Performance "NO Trim" rear main seals. Within 5 minutes of starting the new motor, the rear main was gushing. We assumed that something just got screwed up in the assembly process, so I bought another "NO Trim" seal from TA, we checked the crank and all the area around the seal for burrs, etc., installed the new seal and put the motor back in. Twenty minutes after startup, the rear main is gushing again. I'm wondering first if others have had problems with these seals, or if maybe there is some trick that we are missing in getting it to actually seal? My second question is if there have been problems with these seals, is there an alternative other than the old style rope type seal, or is that my best bet? I certainly don't want to have to pull this motor a 3rd time. Thanks very much for any advice that can be provided. Mark