The short answer is YES, I recently finished adding a '77 nova front clip to my '52 frame. If you drop me your email addy I can send you a bunch of pix.
I choose to straighten the 52 frame so the frame members are parallel starting in front of the rear cab mounts.
The end result is that is looks like GM did it. Did it take a while - yes, I must of measured and leveled and measured 500 times before cutting. One thing that REALLY helped was a laser level that rotates 90 so I could get horizonal and vertical reference points. Home Depot has them. I set it up on the rear most crossmember. A long high quality bubble level is also needed.
To level the frame (my garage floor is like an ocean..) I used 4 pc's of 2x2 box tubing tacked to the frame one one end and 4 sicsor (sp) jacks welded on the bottom.
Pic's will show the process better.
