To Rat, as I mentioned earlier on an engine using shims the shim extends about half way on to the parting line of seal preventing the seal ends from butt completly together. If you cut the shim back so the seals can butt the oil can go arould the back of the seal there the shim should be. It is a little hard to explain, but if you study it you will see what I meen. Also the seal groove in the block is deeper on the pre 55 engines so the neoprene seal will not have the correct presure aginst the crank.
cmayna, if your engine has a rope seal now you will need to drop the crank some only to get the old seal out, the neoprene seals when oiled will slip in and out easily.
