Hey guys. I have a sort of baffeling problem that I'm hoping that one of you had, and will just say "oh yeah, here's what you did wrong." In my 1983 K10, I had a 305 with a 700r4 tranny with about 120,000 hard miles on it. I just finished this years schooling in Idaho, and am about to drive back up the highway home, to Alaska. Basically, on my way to Boise to pick up my driving partner, the motor gave up the ghost. Started knocking bad, spit all it's oil out, and I barelly limped to boise. I had limited options, as we had to be in seattle this weekend and had to drive home (tomorrow). So I went to Napa, plunked down about 700 bucks and picked up a replacement motor. Had to get another 305 as they wouldn't take my 305 on a core replacement for a 350. Oh well, I'm planning on selling this truck at home this summer and picking up another diesel. OK so here's the problem: The new motor leaks oil. Quite a bit. About a quart every 80-100 miles. I've already put 1200 on it, so this is sorta making a mess. The valve covers are sealed up good. So is the oil pan. It only leaks when driving under load (idling doesn't do it). The oil pressure sending unit, along with the intake are sealed up good too. Here's my thought; I halfway remember there being some sort of plastic nipple looking fitting on the passenger side of the block about halfway between the oil pan and the head. Is it possible we left something out? We really don't have time to mess with it, so the truck is going to the shop this afternoon. If anyone has replaced one of these motors and has insight, I'd appreciate it as it would save me a lot of shop time (= big bucks) if I could just tell the guy where the hole is (if that's the case) and to plug it. Oh, some details, the motor has an Edelbrock Performer intake, HEI vacuum advance ignition, performer carb, hedman hedders to dual exhaust and other than that is pretty much stock. Thanks a ton guys.