[Bobcat]

Interesting that you had the rear main seal leak . I had Blair redo my Ponds 482 a while back and he found a big leak when it was on the dyno. He changed rear seals several times and couldn`t get it to stop. Finally modified the seal to put more preload on it as the others went into the groove with almost no pressure . Ran the engine on his test stand for several hours and had no leakage . I put it in the car and had some " weepage " . I had no PCV system , just 4 breathers . Changed to a new PCV system by M/E Wagner and no more "weepage". This system allows you to tune the idle and cruise on the PCV system . Zero blow by ( vapors) out the breathers now and carb is easier to tune. You actually have a slight vaccum in the case at idle now.
Talked to Blair and he and I agree .... the seals available now aren`t what they used to be . Called seal mfg. and asked for tolerances/dimensions and was told no .... which is what I expected. FWIW , seals are now made in Mexico .
Good luck .... with what Blair did , you should have no problems .