Again I'd suggest if you haven't done so already to contact CPP. I realize you didn't see their website however it states:

Quote
Some stock wheels may rub the calipe, it may be necessary to use a spacer. May not work with
some stock wheels. Also, 1947-50 trucks may need
to drill out lower spindle hole from 7/16" to 1/2".
I'd contact them to find out about the spacer they provide for their kit. If they recommend the same 3/16" then something additional is wrong. Either an installation issue or a wheel issue. CPP is very decent when it comes to this kind of problem. In fact if you want to draw some attention to the problem if you do have a further issue with them with them not being willing to help you as you purchased it through someone else, I'd post over at chevytalk.com forums as CPP is a sponsor there with their own forum to address such issues. Drawing attention in public to something if they are to blame will sometimes accomplish more than simply making a telephone call.

My point in my post was merely to point out that several to my mind "major players" had the problem listed.

If you don't mind telling us who did you buy the part from?