I believe the YTM 200 front end has less travel than the DX one. Also, Matticus, when you say you swapped the axle from a ytm 200, you mean the shaft drive "yamahauler" model, as the regular 200 was chain drive. The yamahauler model would also have the 25inch tires all around I believe. I have seen someone on the boards (cant remember who did it) put a 1st gen 200x front end on their DX. It looked like a clean swap, and would be a lot cheaper and plentiful than the tri z front end in the long run, but maybe not quite as good, but close. I have always thought the front end was the weakest point on the DX (forks are just junk). Matticus, lets see some pics of your beast!
THE 80's RAGE! Currently owns:
81, 85 Yamaha Tri Moto 125
83 Yamaha Tri Moto 200 x2
82,83 Yamaha Tri Moto 175 project
85 Yamaha Tri Z 250
84 Kawasaki Tecate 250
84 Honda ATC 70
85 Honda ATC 350X
84 Honda ATC 250R
(2) 84 Honda ATC 200x
82, 83 Honda ATC 185s
81 ATC 200
Lots of other parts and bikes