I've seen a few with the Chasssisworks fronts and they look sweet. Bigblock would be easy with any of the upgraded front suspensions......
I had a 63 about 7 years ago with a 406 and 1 7/8" fenderwell headers and had to notch the shock towers for that. You'd have to take a BIG chunk for a bigblock and would still be crowded. Like those early Novas though. The 63 was my first racecar and I kinda miss it sometimes. Cheap & simple.....
Later,
Johnny