They should be 4-40x1/2" then adjusted length wise from there..

If you plan on using socket heads make sure you grid the heads down to at least 0.168" diameter (same size as the Fox bolts) to avoid binding the case as you tighten down the head. Also use crush pads under the mount lugs if you have aluminum mount pads (these are strips of 1/64 or 1/32" plywood that go between the engine and the motor mount hard pad). These allow for the casting draft angle on the bottom of the stock case mounts to crush the wood a little and avoid distorting the case as it is tightened this avoids piston binding and loss of power.

Best,    DennisT