Can you interchange an 85 tri-z crank cases with an 86 tri-z's crandk cases?

[350xman]

Hi Guys
I have a question about 85 and 86 tri-z crank cases. There is a guy locally selling a 85 tri-z that he started to restore but bought a new trx450r instead and wants to sell it. But he tells me this 85 tri-z has a 6 speed tranny so I went and checked it out and it does have 6 speed tranny but has a different motor serial# then my 86 tri-z does. I know the 85 tri-z's had a 5 speed tranny and not a 6 so, can a 86 tri-z tranny fit into a 85 tri-z's crank case or did he modify something? How can I tell if it is a 86 tri-z bottom end vs a 85 bottom end? Does anyone know what letters and numbers on the motor designate whether its a 86 or 85? Also, can a person swap out the front forks and complete rear end or are they different in fitting to the frame. I know that the 86 has more suspension travel but the actual parts look interchangeable is this correct?
One more thing can I use a stock 85 tri-z's cylinder and get the same power or power band as I have now(on my stock 86 tri-z) or will it be alot different because I have read that the 86 had some different porting and other stuff done to it to make it faster?
Any, info on the matter would be greatly appericated from all the tri-z guros and anyone that knows stuff about the tri-z.
Thanks in ADVANCE!
350xman

[03 ORANGE SHEE]

the outer cases are the same, the 85 internals will fit into 86 cases and vise versa, only the drum, forks and gears are different, the 86 gear ratios are alot closer together than an 85, thats all

[Orangecnty250r]

the outer cases are the same, the 85 internals will fit into 86 cases and vise versa, only the drum, forks and gears are different, the 86 gear ratios are alot closer together than an 85, thats all

Does the crankshaft assembly interchange 38w (85) with the 1rx (86) ??

Mike at vintage needs one for me right now. I'll check he may have sent it out to get rebuilt. They are discontinued ....well the 1 rx for sure

[MTS]

Does the crankshaft assembly interchange 38w (85) with the 1rx (86) ??

Mike at vintage needs one for me right now. I'll check he may have sent it out to get rebuilt. They are discontinued ....well the 1 rx for sure

You betcha they do i have a rebuilt one ill sell ya, Pm me

[Billy Golightly]

They interchange but they are different. The 86 I believe had plugs in the weight holes for a higher crank case compression ratio from the 85s. Nothing no one will ever notice inside a motor though...

[Orangecnty250r]

Thanks

[Bryan Raffa]

They interchange but they are different. The 86 I believe had plugs in the weight holes for a higher crank case compression ratio from the 85s. Nothing no one will ever notice inside a motor though...

Ding,Ding,Ding... we have a winner You are correct!