Hey bud, welcome to the West Coast Swingarm Tri-Z Club! Where'd you find that!
A couple words of advice. #1 was to be really careful taking the front chain buffer pads off. the little threaded inserts can fall down inside the swingarm. but I don't see them on yours anyway. The stock one won't work unless you modify the arm to allow for screw holes on the side like the stock arm has. I was going to add mount screws but I didn't want to sand and weld on mine since it was an NOS item with great paint job and factory decals. #2, see where the rear chain guide bolts
on? you'll notice the stock Z arm has a bracket that goes over the chain guide. I made a custom aluminum bracket go over the guide and space things out right so I could bolt on the stock skid plate and not have a bunch of stacked washers to space the chain guide right. I took some pics of it and need to get them developed.
One other thing, the added length of the west coast arm adds some height to the rear end with the angles of the swingarm and linkage components the way they are on the Tri-Z. to me it was a noticable difference.
Great find and cant wait to see pics of the swingarm on your trike, Mike! :-D
1986 Tecate
1984 Tecate
1985 Tri-Z
1986 ATC350X
1985 ATC250R (2)
1985 ATC125M (2)
1982 ATC70 - Original Owner
175 TriMoto Frame with Pro-Tec Rear Suspension
3-Wheelin' since '82