I agree with everything above.
You can also pick up a shifter relocation kit from keisler auto, which moves the shifter to within about an inch of the factory 5 speed location that would have come with a sbc.
The keisler kit allowed me to use the factory tunnel hole in the floor of my 92 swb truck using the T56.
The nice thing about the T56 is that you can run an unusually low gear, and still not spin the engine much at high speed on the highway...and they shift great.
2000 rpm at a little over 70mph with 4.56 gears and 295/45 R18 tires.
'92 Fullsize, swb rc
5.3L/T56 conversion, comp XR275 HR cam .566/.568 lift 222/224 duration 112 lsa, crane dual springs, trick flow push rods, K&N Filter, Nelson Performance tune, Keisler shifter relocation kit, Boyd Coddington Smoothie II 18x8 235/55 up front, 18x10 295/45 out back, 2/4 drop, eaton lsd w/4.56 gears