Gilmore Belt Drive

Hello everyone. New, but not so new. Kinda hang out in the background, but now need a little help! I bought one of those Gilmore Belt Drives off e-bay for early 340 small block. I of course seem to have gotten all the parts and no instructions. Went to an Alternator shop today to have the pulley removed and the new one pressed on. Well the Chrysler pulley is tapered and fits inside the ring on the face of the alternator and the Gilmore of course is not tapered and if pressed all the way on will contact the ring on the alternator and will not spin. Has anyone installed one of these, and what did you do to make the alt. pulley work?? Any help is appreciated. Thanks, Joe