Joe, there is no crossmember. The motor mounts are side mounts that go between the side of the block and the frame. The 292 has the fuel pump in the middle of the right side of the block(the easiest way to spot a 292). The right motor mount and the fuel pump swap positions between a 250 and a 292. The 292 right motor mount just gets moved forward on the frame. Just means drilling some new holes for the bolts. On later trucks where the 292 was an option the holes are usually already there.