The problem with that cylinder would be the head.... If you use an 85 or 86 YZ you can bolt your Tri-Z head right on, and not have any coolant hose issues.. The YZ head directs the coolant port on the front of the head frontwards where the Tri-Z points it out to the throttle side..
As for using the YZ side cover, not gonna happen, the cover does not have the right casting to accept the Tri-Z kick starter.. ANd the only thing in the case of the YZ you will need is the inner bearing for the powervalve actuator..
The best situation is if you can pick up an 85 or 86 YZ engine, then you can take all the parts you need and switch them over..
Fired my powervalve motor up Friday, runs like a peach, definately gonna need some main jet changes though..
My Ride - 2001 Raptor, HotRods 720 Stroker.
94' Banshee- Bing Bing Bing
85 Tri-Z, 6 Speed, Power Valved, Boyesen Reeds, DG Pipe.
Kids - Lil' Yamahas
Summer rides - 1100 Wave Raider, JS550, 06' V-Max
Winter toy - 95' V-max4