Help Power Brake Install

[JPop]

New to the forum here.

I have owned a 1983 CJ7 with Small Block Chevy just over 2 years. Replaced trans with a Muncie SM465 little more than a year ago.

I am upgrading the manual brakes to power brakes. Have a couple questions.

1. Currently 2 brake lines on master cylinder that go down to what looks like a proportioning valve on frame rail under driver side. The new master cylinder has 4 ports but also came with 2 plugs. I assume I can just plug the 2 unused ports? When would I use all four ports on the master cylinder? If I had disc brakes on all four wheels?

2. Vacuum source. Seems to be a vacuum line between valve cover and holley carb; likely for vacuum advance. Could I tap into this?

Thanks in Advance!

 

[Patrick]

Connect the vacuum line to the dedicated large port in the back of the carb or directly on the intake manifold. Then you must identify all four ports to see which one is used for rear and front circuit. Google the MC’s part number for details.

Have you made a good determination if the MC/booster assembly will mount correctly to your bracket? How about the push rod length and size?