I am upgrading to 4-wheel disk brakes - after talking with Wilwood, they recommended an 8" or 9" dual diaphragm brake booster. I am leaning towards a 9" booster, but both sizes are presenting a challenge that I didn't expect. Silly me... I thought this would be more standardized. I *think* I need a booster with the "short threaded rod" and not the KZ rod or longer rod, but I am not really sure. Can anyone comment on that? I have searched this site extensively and found several threads, but very few posts identify a specific part number. At this point, I have identified the following parts that I believe are correct (short-threaded rod): 1. DSE set up. Unfortunately, I don't like the "snap on" lid for the MC on this particular item. 2. Tuff Stuff 2229A 3. MBM PB9515 The second problem is this: All of the DD Brake Boosters I am seeing have threaded nuts coming off the back of them. I am assuming I will need to make (or buy?) a bracket that attaches to the rear of the booster and connects to the four bolts coming off the stock brake assembly. Is this correct? So my question is this: 1. Is the brake assembly different for a car with stock disc brakes vs a car that originally had drums in the back (like mine did.) [ie, the four bolts currently on the brake assembly weren't on a car like the Trans Ams that had disc brakes?] 2. Are people grinding off the threaded screws on the stock brake assembly and pushing the boosters screws back through the firewall? 3. .....Or..... is there an "intermediate bracket" that the booster is attaching to from one end and the the stock brake assembly bolts are attaching to from the other? Note the small zinc bracket hanging off the back of the DSE Booster. You can also see the four threaded bolts on the DSE. However, these appears to be a lot shorter than the ones on the boosters above. I have heard that a Dual Diaphragm Booster from a 79-81 Trans Am is a direct fit, but havent been able to find a picture yet to clarify this mounting issue.