After reading up on Mud and checking around, I bought a dist for my 76 on EBAY from HEI Dizzy. Ran great at first, now the truck is running rough and backfires on hard acceleration. I would look at other things, except when you touch the screws in the top of the dist cap, you get a good shock. Can't help but think something isnt right there. When I first checked it, the original screws were stripped, so I replaced with slightly larger screws. I really would like to check some sort of schematic, or at least ask the guy who built it what the ****.