You may get lucky and the crank is drilled for a pilot bushing since it's an early 318. Are you sure it's a 68 transmission? VIN stamp on it makes it look like a 76 maybe. I'm not up on the VIN stuff, so I'm probably wrong. If it did turn out to be a 76 model 833, it would be the OD version. Not a bad thing if you don't jerk it around much. There should be a hole in the inner fender for the ball stud, to make it easy to line the weld on bracket up before you weld it. Good luck with the swap. Two guys who aren't newbies to wrenches should easily do it in a weekend.