The Scorp motor leans backwards, x1/9 style, so the cam boxes have different passages to accommodate drain-back from the cam boxes down into the crankcase. Some subtle differences in the engine mounting bosses, but those are easily modified. The dipstick assembly is different due to the different sump pan. Oil pump already mentioned, and I think water pump has larger vanes on it. Sump pan is different in that it has integral baffles (transverse twin-cam instead of longitudinal ala spider). Beta setups are closer than spider.