Welcome to the forum. How did you modify the 38 frame to fit under the 34 truck cab? Reason I ask is about 40 years ago I built a 32 pickup and used a 39 frame, which is essentially the same as yours, and I had to pinch it in and put a bulldog perch on the front because of it's width. Sounds like you have yours figured out though.

Post up some pictures when you get a chance, we love pictures.

Don