Driveshaft Too long?

67 Coupe
4bbl 289
Conversion from 6

I ordered a custom drive shaft and it seems they made it exactly to specs, not leaving the 3/4'' to 1'' play needed for axle travel. I could be wrong but I can't get the u joints past the cener bolt in the diff to bolt them on. I really don't want to have to send it back or risk them saying they did everything I asked and refuse to redo it if it's even wrong. What suggestions do you have for geting it on?

Should I try cutting off a bit of the slip yoke? Grind down the bolt on the diff? Try to move the axle back?