Tested it today with the new top end. Timing isnt right. the base is 1mm thicker than my other cylinder. difference lies at the bottom of the cylinder. the base is not machined down far enough and raises my ports 1mm. throws off the timing something awful and it vibes a good bit.
looks like ill order an actual GT-5 cylinder from gasbike or kings....
also put this quick video together
(may not be live for a bit yet. check back in 20 min)