There are a few different ways to improve the brakes, most of which reduce the power assist and or the line pressure to the calipers. As Ross stated, the easiest is to reduce the vacuum on the brake booster with the vacuum regulator. It must be a vacuum regulator and not a pressure regulator - which will not work for vacuum. I have one to install to fine tune my system in conjunction with other modifications (below).
Another way is to reduce the size and assist pressure by using a smaller brake booster. I've replaced the 10 inch dual diaphragm Cobalt booster with a 7 inch single diaphragm booster, shorter in length and diameter, and almost 2 pounds lighter. It's a 'universal' fit so the Goblin mounting bracket requires modification.
Well I did it, I pulled the trigger and have placed my order. I had to renegotiate with the accountant/wife and rehash the benefit of building a Goblin - versus building something else like a '69 Camaro (big $$$). I got the thumbs up and hit the purchase button. So I will be getting the TC...
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Additionally the brake master cylinder can be increased in diameter to reduce the line pressure at the caliper. The Cobalt master cylinder has a metric piston about 3/4 inch diameter. Replacing with a master cylinder of 1 1/8 inches will reduce the line pressure by about 25%. I purchased a Chevy Astro master cylinder that bolts directly to the 7 inch booster.
220 new holes. Added ..... hummm #40. Removed #20. Love the classic Batman and Robin, wasn't laughing at your guesses. ;)
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My mods are being done to prove out they will work as an alternative to the stock donor parts.