62 Valiant A/C Install questions

That looks like the same poorly-designed compressor mount kit as can be bought everywhere else: guaranteed frustration and money-waste. Talk to Charrlie_S about it; he knows more than just about anyone on the subject of mounting Sanden A/C compressors to Slant-6 engines.

As for that radiator and fan setup: not a prayer it'll fit in your '62 car. Way too wide and way too thick; you'd need to delete the centre chunk of your car's face with a Sawzall for it to fit.