Leaf spring question

[Family affair]

GMC' S seem to be rare on the site but i have some issues. I have a 67 and doing a 5/7 drop with rear flip and rear axle from an 87. I am in need of new leaf spring bushings. From what I have found nobody offers these for the 2wd but they do for the 4wd.Does anyone know if they are the same ? Also I was told that a 73-91 2wd are the same as mine but as far as I can tell the dimensions do not match. Any input ?? Maybe I am measuring wrong ?? Aso not sure on rear shock placement. HELP PLEASE !!!