I just put a vintage air on my 440 six bbl with the sander compressor. I ordered from a Vintage Air distributor for my 6 bbl. I received the kit, but I couldn't ever get the lines to fit on the rear discharge compressor. So after a lot of phone calls with vintage, I had to send in my compressor for a side discharge compressor. The rear discharge won't fit the lines. It has just a bit of interference with the intake manifold, just enough to not fit.
You do have to drill a couple of small bolt holes in the firewall to mount the box in the interior. A plastic plate covers the existing holes. A new cover is included to cover the area where the blower motor used to live, but now is the in and out for the heat and A/C lines. The factory paint on the cover is crap. Plan on painting it. I reshaped the cover to fit better, and painted it body color so it would blend in the engine compartment better. The rest of the installation went according to the instructions. You may have to drill some holes for the condenser bracket to fit the radiator opening. The duct hoses barely fit under the dash and I would recommend securing the hose to the duct so they don't fall off. The lines fit nicely and are not obtrusive. I have not gotten my car running yet, but I am close, so I cannot say how it works. I may paint the compressor black before I charge the system to make it appear sort of stockish looking. The compressor does fit under the stock air cleaner base with out modification, but with very little clearance. This is my first experience with Vintage or any heat/AC system in a car. So I am no expert. Just what I learned. Good luck with yours.