Everything you do to one component puts additional strain on all the others, ie, if you bump up HP the transmission and rear are now potentially your weak links. Is your PG built or stock? Personally, on the street I would like another gear or two, but have never played with any of the overdrive automatics from GM. Seen some feedback though where they can be not so hot unless modified.

So, my vote goes to spending a little on the motor and the rest getting at least a TH350 in there or maybe a TH400.

Don