Need help with front sub frame swap

The '68 frame should be wider. It might be longer too? Not sure. I'd say NO, it won't work. You need an Early A-body frame. I was pretty skeptical about the whole operation at first, but now that it's done I realize it was the only option to save this car and it was only a few steps more than a crossmember replacement. ANYTHING is doable, you just gotta believe.