Oil pickup to pan clearance

First thing i would do is contact Canton, see if that really is the "matching" pickup.
And, you're right, an inch and a half is way too much. Depending on pickup style, i would try for under a half inch.

Edit: I'm kinda surprised that you have a canton pan for a mopar. I thought they did ford pans only, until recently ive seen they do a chevy LS pan or two.
Summit catalog shows one LS pan, one Amc, and fifteen ford pans.