I just completed a head rebuild on my truck and thought while I was at it I would fix the oil pan. Everything went back together fine but when I drove the truck it was leaking from the tranny cover. I assume this is the rear main seal. It's a 1950 3/4 ton with a '49 235. After shutting it down, it leaked about a 8" diameter puddle. After reviewing the postings on the forum, it appears as though this engine is prone to leaking. Should I attempt the fix or is it just going to leak again?

Keep in mind that I bought it not running so this is the first time I have had it running and therefore don't know if it leaked before.