nods - for bolt in swaps - a 2tg is a smoother motor with a shade more grunt ..
to get a 2t or 2tb like what i had better than a 2tg - you need to really start looking at higher compression pistons , rebores , headwork etc etc ..
In theory you can get a 2tB as good or better than a 2tg - but youll need a larger budget , and have to source alot of parts from the states ( where 3t single cams ARE the 4 cyl drag motor to have , not 3tg or 2tg )
rebuild the 2tg , whack in a sweet set of mild cams - and get the head looked at for porting and such , add a good exhaust system and well tuned carby's and i can guarantee you wont be unhappy ! good luck!