66 Dart GT HT Whatsitgonnabe?

With your info, Don, I think I'll try this without brake booster and see how I feel about it. If I'm not satisfied with the brakes, I'll get a VW master cylinder for a model with big brakes, like a Gofl GTI or a Passat.

You'll need a manual brake pushrod (or an adjustable one) which should be fairly easy to find. After you measure the master cylinder bore, you should be able to find a rebuild kit for it pretty easy from Rock Auto or maybe even over there!