Trouble with disc brake conversion

[wareagle_1997]

I recently converted my 70 LWB over to disc. I rebuilt the front end, replaced my brake lines and installed a power booster and new master cylinder while I was at it. I kept drums on the back. Everything was professionally vacuum bled.

The problem that I have now is that I get SOME braking, but not good braking. For instance, I can't get the brakes to lock up even if I slam them on going 30 mph. Also, braking does improve some if I pump them, but it doesn't totally resolve the issue.

A friend told me that even though the catalogs tell you that the pedal is the same for disc and drum, 67-72, there is actually a difference between them, specifically with where the pushrod hole is in the pedal, as well as the angle of the mounting brackets. He said that he had to adjust his pushrod all the way out to resolve the issue with the old pedal, but changing out his brake pedal to a 71 disc pedal really resolved the problem.

Currently, my brakes are much worse than they were before I started the conversion. Any ideas?

Thanks.