brake pre load issues

[33 coupe]

Need the help of the brake Guros!
I am replacing the brake booster on my 67 C10 with a booster from a 72 C10 (remanufactured unit from local auto supply). I have a mater cylinder on the truck that was supposed to be from a 72 C10.
However, when reinstalling the master cylinder on the booster. the master cylinder contacts the rubber gasket on the booster about 1/8" before master cylinder contacts that main mounting surface of the booster. Consequently this leads to about an 1/8" of preload on the piston of the master cylinder, when you start to tighten the nuts down to secure master cylinder to booster. (I have the piston rod out of the booster presently, so I know its not the rod length causing the problem). Do I have the wrong master cylinder or is this preload correct?
Thanks in advance.
Bobby

[michael bustamante]

did you convert over to disc brakes? If so did you ask for a master cylinder for a 72 c10? if you have not switched over to disc brakes then you need to ask for a master cylinder for a 68
Also, when you put on the booster did you also replace the rod going to the pedal?

[33 coupe]

Found the problem. The connecting rod between the pedal and the booster was slightly too long and was forcing the plastic plunger on the booster out and into the piston on the master cylinder. I have to pay more attention next time. Work just like its supposed to!