Power Disc Brake Bracket & Booster Questions

[fasttech]

I am about to start a brake conversion from all drums to 4 wheel disc. My current setup is manual and I have some questions about power brake brackets and booster. I purchased a set of used brackets from one of the members and a new brake booster. See attached pics. The new booster has a threaded type rod that is actually for a late 70s Camaro / Chevelle. I got it cheap so I went for it. From my research the 11" boosters are all the same and only the rods are different. To adapt my new booster to match the old booster I plan to shorten the rod, add some threads, and install a heim rod-end.

Now for the questions... The used brackets I purchased has some included levers. Are these levers standard on all 1/2 trucks with power brakes or just 3/4 and 1 ton trucks? Are these levers for proper alignment with the brake pedal or is it there to create a mechanical advantage of some type? I am trying to figure out if I can eliminate the levers and extend the rod directly from the booster to the brake pedal before I shorten and add treads to the new booster rod.

Also any info on which way the brackets are supposed to be mounted would be helpful since I don't have a starting reference from my manual setup.

Thanks for everyone's help in advance.