I need help fixing up my third gen.

I originally started out as most 16 year olds do, cash in pocket and a dream of either a 69 camaro or 70 chevell. I then bought an 82 Camaro Berlineta with a 305. Since then I bought a 92 RS, and have decided to put the best of both into one. I now have a nice car with a rebuilt 350 tall block with everything from energy cams to the edelbrock perfomer intake and 750 4-barrel carb. I want to put the posi rear end under there, but could I just change out the gears in the pumkin somehow? I hear it is somewhat difficult to do such a thing. Any help? Plus, how would I go about putting a shift kit on my auto transmission? I bought a street scoop with butterflies on ebay since a normal aircleaner doesn't fit on the 350, does that sound weird to put it on my third gen?

if you dont have an in-depth micrometer, dont even bother trying to change the gears. i would just find a rear end out of a camaro that came with 3.23 or 3.42 gears and just change the whole rear end.

shift kit's arent very difficult to install, but you have to be very carefull when you un-bolt the valve body, it has many check balls that will dump out.