I just got around examining a used y-pipe I purchased a week back. Pipe looks like it has been Fresh water used only. No corrosion at all! But, bolting surface has one lug that is not perfectly flat when bolting on transom assembly. One lower lug (not body) has about .003 gap between its surface and Transom assembly. The rest of the lugs and body touches transom assembly. I suspect factory defect. I could build up this area using epoxy paint and then sand down or shim with SS or just assembly with 5200 as sealant and forget about it. Any suggestions.