You have to tune the engine to fuel, you will most-likely run and the # of seasons you wish to run it in. A good acting 305 that likes 89 octane fuel ,and will start and run nicely thru all 4 seasons, at high and low sea levels is-the '83 factory spec'd HO 305. Given the weight of your truck-I'd have at least a 350 to 1 rear gear mated to a 700r4,for nice 70mph highway cruising. This all works well with 6to1 exhaust rockers and 5/8th exhaust primary exhaust headers with scavenger's. A medium rise,dual plane intake,port matched, with an Eldebrock 600 carb,will deliver more than this engine can normally accept. That carb will allow great tune-abillity, to keep your engine very sharp and defineable. A great MSD ignition gives you a solid foundation!
