I'm thinking the holes that are already in the 67 crossmember should give the proper location for the mounts.
I agree. I don't know what the 292 mounts look like but if they are anything like the V-8 mounts on a '72 they will bolt to the crossmember and the top of the frame. If your 292 mounts are from a '67 it should be straight-forward to use the mounts to determine where the holes in the frame need to be.
I'm pretty sure the 292 mounts are not the same as the V-8 mounts since the 292 has staggered mounts. But the design is probably similar.
