[srv1]

Dexron 2 or higher would be fine. The "cheap" stuff is the same as any name brand tranny fluid of that type. Just to let you know. An old trick with GM trannies that arent electronically controlled or electronic lockup torque convertor is to put Type F in instead of the Dexron. Supposedly it is denser than the Dexron giving you a little harsher shift like a shift kit. Also, if that 700R4 is electronic lockup, i would recommend bypassing the computer and put a switch were you can manually lockup the convertor. That is one of the downfalls of the 700R4's being bad trannys.

I would run a QUALITY tranny cooler for your setup. I don't know much about synthetic automatic tranny fluid, but i have seen people race with the "cheap" stuff and had zero problems related to the fluid. Run a good cooler and you should be fine.