parts interchangeability ??

I looked over a 62 Valiant in Salt Lake City that the guy had put a 416 in. He used the pushbutton 904 from a 64. He did a real sanitary job. He had to modify the firewall quite a bit and had relocated the heater to underneath the dash with a custom built heater\air conditioner unit. I know it had Spitfire headers and I was surprised they fit without modification. Unfortunately I didn't examine the Kframe or steering linkage in detail. It seems he told me the 62 had the same kframe as the 64/65 cars and he just used the dropped centerlink from a 64. I know he put later disk brakes on it. He also modified the radiator core support to hold an Afco aluminum radiator with Taurus fan. I was too absorbed in the factory looking heater/AC job that was in it to get into the other details. I still kick myself for not buying that car