A good low cost 2TG is based on 3T bottom end 3T pistons (flycut for 2TG valves)(overbore if you want .020/.040 no perf adv) 3T crank. Have your head done by a prof head man.(standard valves are ok but change springs. A set of reground cams (around 75/35) Match port int and ex 2 x 45 DCOE carbs (solex,s& 40 mm webers are ok but will limit top end)