rb main stud girdle
Usually when structural parts are bolted together, there isn't a gasket, and silicone can't be used. Silicone doesn't squeeze out entirely, and won't allow intimate contact. What does squeeze out can clog passageways. I've seen spun bearings with a chunk of silicone stuck in the crank. I've also seen spun main bearings when silicone was used to seal an engine case together, and didn't allow the proper crush on the bearings. In such situations, I've used Permatex Aviation Gasket Sealer, but Mopar has a special product called Bed Plate Sealer, which would probably be good on the #5 main cap. I have a feeling that the pan rail of a big block Mopar isn't accurately machined enough for that, but they make another sealant that says it will fill irregularities up to .030"
Here's the Bed Plate Sealant
Usually when structural parts are bolted together, there isn't a gasket, and silicone can't be used. Silicone doesn't squeeze out entirely, and won't allow intimate contact. What does squeeze out can clog passageways. I've seen spun bearings with a chunk of silicone stuck in the crank. I've also seen spun main bearings when silicone was used to seal an engine case together, and didn't allow the proper crush on the bearings. In such situations, I've used Permatex Aviation Gasket Sealer, but Mopar has a special product called Bed Plate Sealer, which would probably be good on the #5 main cap. I have a feeling that the pan rail of a big block Mopar isn't accurately machined enough for that, but they make another sealant that says it will fill irregularities up to .030"
Here's the Bed Plate Sealant
