I have a 292 to replace the 250 in my '70 K5 Chevy Blazer. The motor mount on the passenger side is not in the same location on the 292 (moved forward about 4 inches). Do I need to get a crossmember for a 292 to complete the change?

The upper portion of the engine mount frame tower looks like it will relocate to existing holes in the top of the frame rails however, the bottom of the frame tower that would normally bolt to the crossmember is left unsupported when moved forward - not good. Any Ideas??