Then the unit had to be leveled front to back. Instructions say to block it up, which was easier said than done given the slant of the floor under there. Then mark the position of the holes in the front mounting bracket. Note - there is a good flat spot on the bottom of the unit where the drain is to get a small level in there.
Now drilling the holes is a whole nuther matter. Fortunately, I remembered a gift I'd gotten many years ago and never had a use for until now - a right angle drill. This contraption just fit up inside the dash area to drill the holes.
Also used the supplied spacers, but had to grind about 1/4 inch off of them. They would have sat flush on the firewall if I'd been bolting through it, so needed to remove roughly the thickness of the firewall metal, a flat washer and the head of the bolt. I guestimated on this step
