OK on the white mark. Yes that would force you advance the timing 35 degrees to get it to line up at the same point as the new damper. Looks like the green mark on the old damper was correct. No wonder it was hard to crank when hot and idling messed up... you had 45 degrees initial timing in it! Probably it was detonating too when it was missing and backfiring.
Fair warning: You won't get the torque you had with the base timing so far advanced.
BTW, I would be running cylinder compressions on all cylinders. Mostly to get some clues as to what you have for a piston + cam combination. KB's can be higher compression, or just Silvolite low compression stock-replacement pistons sold as KB's. And get a head casting number; it ought to be 7 digits, under a valve cover, cast on one of the runners.
