Hi Tom. The trans will work behind anything. As far as balance goes, since it's a 69', everything will work behind a internally balanced engine. When you mix in a cast crank external balance deal, the converter needing weights or a special flexplate becomes a issue. I've never done any mix & match stuff, so I can't really tell you specific parts/numbers, if that's the case. As far as the cam and stall speed, I've driven several cars with cams and the stock 340 converter, but a cam with more then 225/230*@.050 intake duration can be a little uncomfortable for a driver that's in a lot of idling situations. I never really had a issue neutraling a lot at lights and such, but that was just me. The most aggressive timing that can be run also helps. From a performance standpoint, they all stalled/powerbraked in the 2000rpm range. Not the best for getup and go, but were workable.
Hope i'm understand what your asking.....lol. Just let me know, Rick