With the engine set up like you have it, you can make no.1 on the distributor anywhere you want. Just want to position the dist. in a fashion that allows you room to turn it when you put the timing light on it after you get it running. The postion of the slot has nothing to do with the timing of it. From the factory, no.1 was at about the 7 o clock postion when viewed from the top of the dist. Then wire it clockwise 1-8-4-3-6-5-7-2.