Problem with power brake swap

[fs64]

Swap utilizing a used 2001 GMC booster with a new 1970 Buick estate wagon master cyl. ( Autozone M-1489) utilizing Captain fab bracket. (Nice piece: need it, get it!!!)
All new lines, shoes, hoses and wheel cyls. new drums on front, turned drums on rear. Initially had trouble bleeding front brakes, found that intermediate rod was putting pressure on the master in the resting position and apparently not allowing fluid from reservoir to refill the cylinder. Adding a spacer between the booster and master allowed us to bleed fronts without further problem. Plan was to cut intermediate rod down to correct length.
Pedal is high and solid, however the truck does not stop well with pedal as far to floor as it will go. It is not soft and booster checks out fine. Removed the spacer from between the booster / master and it seemed to help minimally? The pedal to booster rod is adjusted to about an 1/8 of an inch and booster rod starts in motion with same. Placed clay between booster and master and clearance is about 1/32. Front drums are adjusted up well with appropriate drag. Rears are adjusted a little a little looser and are cut slightly larger than the max spec. but they will lock up when brakes are applied hard.
Current plan is to replace master cyl. with a NAPA # NMC P1971 and try again.
Any help, recommendations or suggestions are greatly appreciated. ( just don't mention discs )
Thank you all,
Todd