Pat - I installed the same pan on my 393 last Monday with no problems, but I'm not using a girdle. I hope the mods work out.
What pan gaskets are you using? I was all set to use the 4 piece Fel Pro setup as Canton recommends, but after talking to a few guys on Corral.net, I went with the Ford one piece rubber/steel gasket. It fit great, and supposedly is the only gasket not to leak with Canton pans. We'll see.
Here's another question - Since I'm using a Canton screw in
oil dipstick (screws into the right side of the pan) I need to find a solution for the stock dipstick location on the left side of my block (beneath the driver-side motor mount). When I was putting on the pan, I realized this whole needed to be blocked off some how. Maybe they make small freeze plugs (about the size of a small bolt) to block off the hole? What did you do about this?