Hello and thanks for the help and input over the yrs.

I've decided to replace the rear main seal on my 312 engine. I, rebuilt the engine about 3yrs. ago. If you had the choice of rear main seal black rubber (neoprene) or the softer orange type (silicone?) which would you use? Both are from best gaskets. In fact the now synthetic rope seal is made by best gaskets. But any way I'm leaning toward the orange silicone seal as I, just ordered one on e-bay....I, hope I'm right :-) The leak I'm fairly certain was because I, used permatext II and it looks as though the hot engine oil dissolved it. This time I'm planning to use RTV. The side seal retainer and the bolts I, used permatex II. It failed

Jeff