Differences between 81 and 83 185S frames?

[Scootertrash]

Are 81 and 83 185S frames identical? A buddy has an 83 1856S that's had the frame welded rather sloppily, and he has a 81 185S frame I told him he should swap them out, but he says someone told him they aren't the same. Are they? Will the 83 suspended front forks fit the steering head on the 81 frame?
Thanks!

[3wheelrider]

Yes -it will go on the same. the only concern is the airbox will also have to be swapped & it would then draw air to the box from under the seat (insteqd of at the neck and thru the frame)-which is not as good in mud/water