The factory flex plates are usually drilled only to match up to the convertor the vehicle was built with. I believe the 700R4 uses the same bolt pattern as a TH350 while a Powerglide is different. If you are going with an aftermarket piece, they are usually drilled for both.
I would take a 700R4 over the T-5, especially if pulling a trailer. Only problen with the 700 is a fairly large gap between first and second, but it is a given with the 700 or 4L60.
I could not find the specs for the Clifford Cam. You need something with torque at very low rpm and if it maxs out at 4500rpm you would still Be OK. Have Clifford send the specs on their diffent cams and check out Comp cams. Also you may want to check into the Offy manifold as it is supposed to be better for the street. It would be worthwhile for you to talk to Tom Langdon at Stovebolt Engine Co. He can probably give you best advice you can get on the combo and application...
