U bolts are whipping me

[65Gregg]

I'm in the process of bolting up my fresh rear end and have gotten into a fight with the U bolts. They barely fit through the axle perches, not a diameter issue but the distance they are spread. When I try to put my lowering blocks on, well it ain't gonna happen. The holes in the blocks are about 1/2 inch wider than the u bolts. I haven't tried to see how they fit in the trailing arms yet but my old and tired butt can't spread them apart enough to fit the blocks. Any ideas or suggestions. If they fit the trailing arms ok at the current width I'll probably have the blocks machined to fit.