I have a 77 20R Pickup that I just did the GM ignition bypass to, and a magnetic distributor off an '80 pickup. Timing seems a little weird. there are two marks on the pulley and one line on the block... no numbers and no other hash marks. I assume the first mark on the pulley (closer to the pass side) is 0° TDC and the second mark to the right of it is 8° BTDC? but I'm not too sure. It will barely Idle at the "8°" mark and dies on the 0° mark. Right now it seems to run great about an inch past (to the right) the "8°" mark where there is nothing to line up with the block mark, do I have the distributor off a tooth? Sorry if this is confusing but I don't know how much better I can explain it.
Get the #1 piston back on top dead center of the compression stroke. Where ever the rotor points is plug #1. Wire up the cap in order, most are printed on top. You then rotate the crank counter clockwise a tiny bit for BTDC timing and ear it in to the best place. Check that with a timing light. You'll probably have to reindexed the dizzy a tooth or two. You should sort it out easy enough. 10-18 BTDC works best depending on your fuel and carb tuning.
once I stabbed my dizzy one tooth off and I swapped the wires to the next wire clockwise cause I didn't feel like pulling it back out at the time
