O.K. I ordered my long block today. Now I'm looking at my parts piles and wondering if I should use the Mallory mechanical advance dist. I got off Ebay. It is a comp 9000 unilite distributer, and I have the matching coil set up with the internal balast resister. I remember last year a few of you commenting on vacuum vs. mechanical. How big of a deal is it to use a mechanical distributor?(this is going on a 460 ford engine for street use only)