I'm in the middle of trying one of 440 Source Viton rear main seal on a motor I'm having issues on sealing the rear main seal I haven't had one leak in a lot of years and now I've had several motors leak I may have a issue with the new batch of 10 rear main seals I bought earlier this year being bad
I'll know more tomorrow on if this is a good fix or not after running on the engine run stand, I'll post my results