I would go beyond just aligning the (roughly) 1/2 inch subframe alignment holes. I would get the frame alignment measurements from the shop manuals (Supplement for '67) and test them with a plumb bob and masking tape on the floor underneath the vehicle.
I just installed the subframe using 1/2 inch bolts to align the subframe alignment holes and found later my measurements were still off about 1/2 inch. I was sure that was NOT going to be good enough to prevent issues down the road (panel and front wheel alighnments)
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
