The width is in the cross members, not in the frame itself. I would think you would want to keep your 36" frame or you would have all kinds of problems in the front end. However, you could add frame channels and either use your 36" cross members, shim the 34 " cross members an inch on each end, or fabricate your own and bolt it together. Flange bolts worked on class 8 trucks for 40 years until they went to Huck bolts in the mid 90's.
