it doesn't actually matter which one you use for #1 you just have to have the rotor line up with one of the terminals inside the cap and the rest just go in order,(you would of course have to move the wires to the correct relative position) the important part is getting the little tang on the bottom of the distributor lined up with the slot in the oil pump.If you haven't turned the engine at all with the distributor out you should be able to just put it back in, but if you move the engine with the distributor out, the oil pump gets out of sync. It will be much more entertaining. You can put the distributor in as many ways as there is teeth on the gear but unless it lines up with the oil pump it won't go in all the way. Every other tooth it seems like could be fine as long as the rotor lines up with one of the terminals. The reason I mention getting the oil pump lined up properly is there was a post fairly recently the fella didn't have the distributor down far enough to engage the oil pump. But down far enough to engage the gears, it would run but had no oil pressure.