MSD ignition installed, now I'm thinking transmission time?

Well I want to stick with an automatic transmission, so Rumble I suppose that A-500 would be the one for me. Was it ever built to bolt up to a Slant 6? I thought (coulda sworn) I had seen AOD /6 cars before.... I do plan on installing power disc brakes, headers and carb but I don't think I'll have issues with fitment on an AOD transmission. Electric fan is also on the list.... Jegs and Summit have soem good cheap 16" kits that I have played with in the past. With summer coming, that's probably a necessity :)