I'm a believer in modern synthetic oils for the transmission and rear-end. Lucas makes some GL-4 and GL-5 equivalent oils.
For the engine, there are several options. Modern oils have the zinc phosphates removed....your older flat tappet engine relies on that as an extreme pressure agent to protect the cam and lifters. Even the diesel oils have it removed now, so look for a racing oil that contains either Zinc Dithiophosphate or Zinc dialkyldithiophosphates (ZDDP). Valvoline makes one now and so does Brad Penn and Royal Purple (not all of the Royal Purple oils have added ZDDP, so watch out there). Another option is to buy some good oil and add a ZDDP additive. I found the Valvoline VR1 in both a synthetic oil and a straight petroleum oil...that seems to be the best deal, but stores seem to be stocking some unusual viscosity oils, so you may have to shop around or ask them to get a case for you if you want 30wt or 10w40.