84XC500 motor in 510 frame-opinions wanted

Looks like my 82 it465 is going to one of my brothers. In trade I am getting 84 XC500. My main priority is the 390 and I would like to use the shocks and maybe forks from the 500 for the 390. I may be able to acquire a single shock air cooled 510 basket case. I am a big (synonym for FAT) guy and the heavier spring rate from the 4t appeals to me. I am not going to scrap the rest of the XC by any means but if possible I would like to see if this could work. I don't want to do anything I can't undo later. Just thinking at this point. Any input would be appreciated.
Geary

Geary, shocks are longer and have different valveing in the 84's than your 390. Will they work??? I dont know but been thinking about trying that myself. I'm kinda big boned too, 6'2" 275 and all my stock shocks are too soft. just got a set today from a guy that is braver than me so will see how stiffer ones work. The 84 shocks have the same travel just the lower mounting is different, heh, its only metal. Scott W.

The forks with triple clamps, and the double leading shoe front wheel will bolt right on the 390. The shocks won't. The upper and lower mounts are different on the 83-84's.. I have 82 shocks with the 82 style swingarm. They would bolt right on the 390 frame. You would still have to put stiffer springs on them though. I would be interested in the 84 frame and ? if you are interested in dickering.

I will keep it in mind. Right now I have quite a few ideas and not much to back them up. My first priority as far as me spending money goes is the 390. Using the shocks was just an idea as a temporary measure anyway. I am not in a hurry, I have till next April to get it ready for the next Desert 100. I may just ride the 500 this year although it is hard to not ride my 525exc. I just have this daydream of the 500 motor in a street legal 510 frame and setting up an extra set of wheels for the street. I think it would be a kick in the butt! However just idle speculation at this point. for now I don't want to do anything to either bike that I can't easily undo. How much would the 82 shocks/swingarm raise the seat height? I don't want to get it any higher than I have to. If I decide to actually break up the 500 permanently I will let you know. My brother and I had so much fun in the vintage class I can hardly think about anything else but getting these old girls freshened up!

04-28-10
Well after spending money on billet manifold and reeds I have decided to concentrate on the 390 and let this go. My plan is to install the manifold, reeds, and clean out the carb and see how much better it runs. I have it in the classifieds so wont go into detail here.