It has been a wee while since i last had the cams out of my sportster and it is a 93 and may be different from yours but i remember i turned the engine till the pinion gear was in the correct place then got the rear exhaust cam in place and the front inlet cam and the slipped the rear inlet cam over the other 2 so that the 3 marks on the rear inlet cam line up correctly with the pinion gear and the 2 adjacent cams and the placed the front exhaust cam in so that all was lined up
There should be a picture or diagram in your service manual that shows the correct alignment of all the cams
Brian