Convert the 62T cases to a big single carb (48mm) and its more reliable and you have higher entering air velocity, Consider the fact though that with a ported right setup engine a single carb wont cut it for WOT runs (leans out the engine... not good) but if your not really into that (most arent) then I think its the way to go. Get a prop, pitch you want will depend on personal preference, alot of peopl use the 13/16 3mm cutback, Im 200 lbs so Im in your boat, I have a 14.5x18.5 currently but may switch for more bottom end. Ported cylinders will help that b-pipe recognize a lot of power. 180 psi head or so.
If you switch to single carb, you can sell the 38's and probably not spend too much converting a single.
Bottom line, if you can jet a carb (why converting to single is all that much better!) then get your cylinders ported by LPW, thats the best bang for the buck hands down.