Will the '70 grille interchange with the other single headlamp CUDA front ends? Obviously the '71 is quite different but I wasn't sure with the later models.
Thanks!

The header panel in a 70 is very different than a 71-74 and I believe that requires a 70 Header panel to use a 70 grille.

Aside from that it should be a drop in.

70 Header Panel


71-74 Header Panel

While you could work out the issuses with the header panel, keeping the 72 header if you wish,...the biggest problem is the depth of the fender buckets, the 72-4 fenders mount the headlight much further forward,....you'd need to do some surgery to get the headlite recessed enough to mount the 70 grille headlite corner end to fit properly,....it can be done, and has been done, but it's not as simple as drilling a few holes, you'll need to relocate some sheetmetal in the inner headlite area