Email this man - Jeff Bordelon. He swapped a the D&D viper spec into my car. Long story short, me breaky stock T-56. The D&D swap requires that you buy a different drive shaft, clutch&pressure plate as well. The input shaft is 26spline. If you order from D&D specify its going into mustang 4 cammer, your swap should be close to mine. The tranny came with the correct bellhousing for my car. I think the cast iron blocks are the same in both cars. Jeff did have to fabricate a cross member, but it really was no big deal. Took 30 mins to fab the cross member. He can provide you with more specifics.