I just found out brake pedal travel is adjusted out via the adjustabe pushrod on the master cylinder side of the booster. Question is where to you buy this rod as my replacement booster doesnt have a knurled tip with a hex head for adjustment.

 

That is not for brake pedal adjustment. It's for proper booster to master cylinder engagement.
The push rod should extend past the face of the booster as follows:

1976: 0.880-0.895 in.

1977-81: 0.931-0.946 in.

1982-86: 0.980-0.995 in.

If you get this adjustment too far into the master cylinder, it will cover the compensation holes in the master cylinder and you will find after driving a couple of miles your brakes will start applying themselves without you touching the pedal.

 

Rusty, You sure you have the right pedal for the type brakes the truck has?


I say this because someone asked about swapping from manual to power and was going to use the non-power pedal. This cant be done as the booster/master rods connection the pedal shaft at different places and can thru off the ratio and travel.


I know for 81 the power & non-power are different as I posted pictures of them.


Cant remember if the rod from pedal to booster could be adjusted or not. When I get out to the garage again I will try and find the power pedal & rod to see if it can be adjusted.
Dave ----