Spoke to Andy last night,
The engine kit is a standard one mate, no body makes anything for that engine
he has however selected the performance cam for that year and says for $250 can get it reprofiled for a little more performance 30hp ish. Pistons in the kit are cast and not forged as forged would be custom jobs and run around $800 if they can find a blank but he says the cast ones will be fine with up to 125hp nitrous shot. Kit includes cam,pistons,bearings,oilpump,lifters,valves,pushrods,rockers,gaskets everything appart from crank and rods. You could run a better carb seeing as you already have a 4brl and of course electric fuel pump cooling fan etc will all help. Cooling fan is 10hp for a beltdriven type