It's a whole lot of stuff. Suspension is a biggie. There are several companies that offer weld in modern suspension options. You have to beef up a lot of the car.
Best bet is to go YouTube and other internet sources and check out the info on swaps.
Search on here, several members have done some research on the subject.
Chevy runs deep, don't step in Chevy.
chevy runs deep, Don't step in chevy!
67 Coupe 289 - TCI C4 w/2k stall; Holley 4150 570cfm; Performer intake; mild cam; Pertronix HEI; 302 heads; Roller Tips; Hedman Tri-Y headers; H-pipe w/Flowmaster 40's; 9 in posi 3.50; 205/50-17F; 225/50-17R.