2.8 tranny will not work... too weak... you will need to get a HEI distributor.... what are you talkin about an adaptor to take it down to a 2bbl? you can run a 4bbl on a 305 jus fine. honestly its not worth it imo, you will be spending more money on it then you think to get this too work. plus your puttin a 305 in now which if you do add performace goodies will never see more than 250-300crank hp and be reliable...