I've done the tranny relearn and still shifts terribly. I'll be doing the tranny probably by the end of the month.
Depending on the power you're putting out, that may be why the transmission is shifting terribly. They aren't intended to behave well under power levels higher than stock.
after the transmission upgrade can I go to a higher level?
After a built transmission (depending on the level of the build) you can put down stupid amounts of power. Even a mildly built transmission is capable of holding as much power as stock engine internals.
What lift pump do you commend?
I've had great luck with the Airdog 165 I've got on my truck. FASS is the other big name in lift pumps, but there are other manufacturers as well.
We have some great vendors here - check out the
vendors section (clicky) to see what they have to offer in go-fast parts. I've only personally dealt with Henry (Creatures of the Night Performance), Idaho Rob (Adrenaline Truck Performance), and Guy (SoCal Diesel), but all the vendors here are good people.