Rear end yoke interchange??

[Terakilla]

To start off I am putting a LT 4.3L V8 with a 4L60-E trans In my 72 short step that orig had a 307, I do not know the trans and the only thing I know about the rear is it's a 12 bolt. I'm having trouble with the driveshaft from the new engine fitting my old rear end. The car that the engi e came out of has a 10 bolt rear end. The new driveshafts u joint is both too wide to fit the trucks yoke and the caps are a little bit bigger than the old ones. So what I'm basically asking is what and will any other chevy rear end yokes fit this trucks. It will save me the trouble of taking the old yoke to a machine shop to bring it down