They are the same pattern. The rears use 30mm, and 28mm pistons. The front's are 40mm, and 36mm, but some have 44mm, and 38mm pistons (the 944S2's I think). You need larger brakes in front to counteract the weight shifting forward when brakes are applied. You could use the rears in the front with some two piston 911's in the rear (not sure of bolt pattern, or piston size) they are both Brembo calipers. So, at least they would have the same style
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans
1962 SC 1776cc SP 944NA brakes, 993 wheels
VKG