Power booster and master cylinder compatibility

[GaryR]

It turned out that the power booster on my 65 T-bird was bad.  (I think its a broken internal spring.)  I've decided that since I'm going to have things apart anyway, I would upgrade to a dual-reservoir master cylinder.  I've seen postings on other boards about swaps on 64 and 65 T-birds using master cylinders from a 73 Mustang and a 67 T-bird and have corresponded with one of the posters.  That person used the 67 T-bird MC, but said he had to install a 1/2-inch spacer between the MC and booster.  My question is, how can I minimize my trial and error in selecting a MC and how can I determine if and how much of a spacer is/will be needed when installing the MC onto the rebuilt T-bird power booster.  I haven't been able to find anything online that gives any information about MC piston travel or booster pushrod length.  I'm not opposed to trial and error experimentation, I just can't afford too much of it.  

Gary

[enjenjo]

Basically, there are two configuations used on master cylinder/booster combinations, Bendix, and Moraine. The Moraine has a longer pushrod from the face of the booster. You can even find both types listed for the same car, sometimes they used both depending on manufacturing location.  I have a tool I made to measure this difference, but I don't know of a commercially available one like it.  so the only suggestion I have is to find out what booster you have, and try to get a master cylinder that matches.

[GaryR]

Thanks, I'll do that.  -Gary