Proportion valve questions

When I bought my 1974 cj5 it had disk brakes already installed on the front but It still had the original master with equal resivors. It would not lock the wheels up so I swap the master for a 1979 manual brake set up but I am not sure what proportion valve I have. The identifications I can find on it is Wagner 228-3 but I cant find anywhere to cross the number? Also it has a hook up for a brake light switch on the valve was the stock one like this?

 

Brake light switch on valve is for the idiot light in the dash, not the stop lights. Don't know if you have a stock part or the on for disc set up. You could always get an aftermarket adjustable one and set it where you want. They aren't a lot of $. This guy is about 2 miles from me, and yes have always been treated well there.
http://www.jeeperz-creeperz.com/adjustable-proportioning-valve-p-7469.html

 

Would a valve out of a 1979 Chevy Nova work?

 

Should.

I get the valves for about '82 chevy S-10 or GMC S-15 trucks.
They have the correct fitting sizes for Jeep, and usually cost less.