You have a long stroke, std oppy bore (3.44") engine, and you need the 46 ARC rod. Then, the ARC rod is made for the AVS pistons, which have the wrist pin located higher in the piston. Together, the wrong rods, and stock piston would account for the piston being 1/2" out of the hole. Have you made any full revolutions with the rods and cam in place? The 46 rod has the rod cap on an angle, compared to the 42 rods which are straigh to the beam....the 42 rod wont clear the cam when combined with a long stroke crank.