Ditch the edge juice for a drag comp and a good set of mechanical gauges and ditch the silver 62 for a sps 62. I've run that combo. Fun as hell.
If you don't want to do tranny upgrades but want a fun, reliable, 300rwhp, good MPG then do an edge ez and rv275 injectors. Won't hurt the tranny, be totally reliable, easy on the injection pump, no smoke, and get some nice mileage (I was getting 20mpg with this). Those were the best mod combo I've ever tried. Stock turbo handled it with ease. I do recommend a good fuel system. An airdog or raptor setup.
As far as tranny upgrades, if your not looking for more than 350-400hp then a valvebody upgrade and a little common sense is all you will ever need for that tranny.
Good advice on checking for the 53 block.