xj to the xv fork swap nightmare

i just picked up an 81 seca... runs nice looks haggard and rides rough. the fork seals were gushing and if you put air to them they'd be flat in 5 mins. Enter a xv920 virago I've had for a while now. Its a basket case and dont want to mess with it. the tubes are supposed to be the same size and they are both 81s . what a disaster im about to convey . l pulled just the tubes and tried to swap. oops 920 tubes wont fit 750 triple tree.Ok ill swap triples, error the seca has ball brgs. virago tapered rollers. Ok upgrade seca to tapered brgs. nope no way to remove 920 races. wait it gets better. ok tripple trees with ball brg installed. seca head lt bucket wont bolt up to 920 trips. alright swap bucket and gauges. two weeks later im tire of wire. i got the wiring done , whew. i swap the calipers and when i try to put the seca wheel on the 920 forks guess what i discovered. yhe rotors are an inch bigger on the seca wheel!!!. so by now the bikes been down most of the summer and im jonesing for a ride so easy peasey i put the 920 wheel on and take it for a spin . the tire is abt half life (not) at about 65mph i feel a horrible vibration starting and being an idiot try to push past it . it continues to wheel hop to 75 mph where i back off the juice and enter the worst hi speed wobble iv ever experienced but hang on an survive.back at the shop i figure ill swap rotors and be back on the street in short order. now i discover to my dismay that although the wheels appear to be identical alloy the seca wheel is about a 1/4 inch narrower at the hub and is sloppy on the axle ok i throw a spacer in the mix and now the left caliper is a1/4 shy of fitting back on the fork tubes.im buying a honda next year lol.

 

It's much easier to just replace the eals on the 750 forks. All the parts necessary are avialble through @chacal. You can upgrade to roller bearings at the same time.
As you found, swapping the Virago front end leads to handling and fitment issues.