I used aluminum bar to build the struts. They are 3" shorter than the shocks that were on the bike, but the 3" springs under the seat keep the bike a tall ride. Lowering the tail end changed the fork angle making the steering more stable.
A friend really helped by machining aluminum slugs and steel end caps to solid mount the engine. It was a beautiful job and done by a master machinist. The bike actually vibrated less, the old rubber mounts were probably worn out. I think I may be on to something here, old worn parts cause vibration, amazing.
I installed a new chain and sprockets and went up one tooth, from 15 to 16, on the counter shaft, which lowed the RPM's from about 5100@70MPH to 4300@70MPH. The new sprockets and chain further reduced vibration. I'm sure that the lower RPM reduced vibration, I'm also sure that the worn out chain didn't help.
I built a rack to hold the 3 gallon tank. The rack is in the same place as the old radio box but had to be a little higher in order to gravity feed the carburetors.
I built a box at the front of the rack to hold a backrest from my Harley. The seating position on the bike is quite upright and riding at speed is like doing a continuous pull-up and the backrest will give a little relief.
All the big stuff is done, but I've still got a long list of small stuff that still has to be done. But with a little luck I should be ready to head for Barstow on June 15 and give The Stampede a go.