I use hylomar on all my stuff from manual trannys to engines outboards, cycles, 2 cycles lown mowers and everything in between.It was originally used on rolls royce jet engines and has found it's way to the automotive industry finally. I used it on my puch e50/polini kit case halves last year i've put over 2500 miles on it so far and no problems !
I highly recommend it. I use the tubes shown on the right let it sit 15 minutes to stiffen slightly and put together a little goes a long way just wet both halves less than paper thin.HTH.jim http://www.valco-cp.com/Hylomar.htm
P.S. you can find it also at any good specialty car shop.