ive done this in quite a few foxes, but no sn's, as for the crossmember, ive had good luck making a simple ~4x6" steel plate (3/16" works good) with 6 holes in it, 2 go into the tranny mount, other 4 nut and bolt to the existing crossmember, way easier than moving the crossmember, your driveshaft yoke should work (as long as a 94 t5 has the same yoke as a fox t5), but i think your going to have a driveshaft length issue, as a c4 is about 1/2" shorther than a fox t5, and if my mind serves me correctly the 94-95 t5's are an inch or so longer than a fox t5 so ur going to be coming up short at least an inch or 2. other than that its pretty easy job, make sure if your going to have a high stall u get a BIG tranny cooler as the c4's over heat real quick with hs converters