sam,
I think those are the northern sport mod rules, southern sport mod rules require a hyd cam, and they check cranking psi(limited to 175 lbs after five rotations), no limit on c.r. per say, just on the cranking psi. I to assume he is speaking of "a" mods, here in texas people usally call mods mods and sportmods sportmods. I own, drive and build one of each of these money pits