TJP- I doubled checked yesterday. I tested the vacuum at the booster (26"). Yesterday was the first day since I installed the vacuum pump that I could test the car in the driveway, not just the shop. The vacuum booster made a marginal difference. so I definitely still have a problem.

I went onto the getdiscbrakes web site to try and find some more info on the brake calipers. When you click on the link to the brakes a message pops up saying they currently are not stocking brake calipers for 68 Chargers at this time. Wonder if they knew they had a problem.
As far as buying a new booster I'll look into this one from Dr Diff. https://www.doctordiff.com/bendix-style-dual-diaphragm-booster.html
I'm also thinking I should buy a new proportioning valve. As I mentioned earlier the passages in the new one that Fine lines sent me were smaller than the one that was matched up with my manual drums. I'm now questioning everything that I got from this company.