Has anyone had any experience stuffing a 390 into an early coupe? If so, what modifications are necessary. I've looked for a build site and I'm coming up empty.
'67-'68 should be a a basically drop in process, though if you don't have stiffer springs, I'd recommend getting some. '65-'66 however can get hairy for big blocks - shock towers will probably need to be notched.
No the 65-66's are narrower between the shock towers than the 67-70's. This was the reason Ford redsigned the whole car for 67, just so they could get a big block in there.