start with the basics.. things youd do anyways like leads, plugs and points (if you have them). Chances are its carby but no point in getting the carby rekitted or buying a new holley if plugs are filthy and timing is miles out (points). I had a 350 chev and T350 in an HJ ute and the wheels would fry at under 2,000 rpm on the brake! loose

the trannies are pretty straight forward i think. maybe just drop oil and change filter (in your box) before you go spending money at the mechanics. also check your vacuum line isnt perished etc. that will impact on the shift