I tried to take pics but the camera battery is dead. I'll get those later. Here's the deal, the 50v's motor mount on the head is roughly an inch lower than the motor mount on the av78/av88/av89 etc cylinder head. Because of this you can't use a newer cylinder head unless you make brackets to extend the mount (like if you want to run a high compression head or a watercooled kit). Of course you can use the stock head with most cylinders/motors.