just completed the switch myself. You need a case fill C4. A 157 tooth bell and flex plate and block spacer plate. Shifter I used a hurst quarter stick it came with everything i needed. Need to move the cross member forward as far as it will go by grinding the spot welds off the end tubes and slide the mount forward and weld the tubes back in place. New bolts for the flex plate to crank. everything else bolted right up.
My car is track only so I have a 4000 stall. I have a reverse manual valvebody so I dont need a kick down I shift the car manually. The car is fuel injected. I went with the redneck c4 package.
if you cant find a c4 blockplate and dont mind cutting a hole in your t5 plate , the t5 block plate works perfect for the small bell c4. just have to cut an opening at the bottom so you can get to the converter bolts. holcomb motorsports used to sell the shifter conversion kit,(dunno if they still do) it came with a 1/4 stick and the mounting plate to put in the stock location. was somewhere around 200 bux i think.