take off head, turn piston to bottom, place a soda straw on piston, make a mark on straw level with top of cylinder, turn piston to top, make straw level with cylinder, measure between two marks
im pretty sure its a gt5 ive got a zeda80 ported out cylinder on it and that head was from the GT80 kit i got in 2016 i might put my newest creation on there tho i picked up one of the ZL short crank bottom end from MZMiami and ive got the DioReed and a Mikuni vm26 to put on it i just wanna grab either that oversized Thruster looking exhaust or a MZ65