Hi Michel,
Nice bike. I am a huge fan of Husky autos. I have plans of building one like yours, only I was going to use an '86 CR500 top end, an AE500 crank (with 430 AE left half shaft) in 430AE crankcases, dropped into an '84 WR400 frame. This is the bike that I think that Husqvarna should have made

. I just hope that I don't run into clearance issues with the exhaust pipe header, as the 500 cylinder is about 10mm higher than the 430. I may also have to make the rear cone section of the pipe longer to suit the 500. I see that the tank on your bike looks like a cut down '83 alloy one . I imagine that this would have taken a lot of work . I intend to use the original WR400 tank, as it should bolt straight on .