I bought the one from wilwood. It did the 2-3 conversion, and has a rear adjustment built in.

Wilwood Disc Brakes 260-11179 - Wilwood Brake Proportioning Valves - Overview - SummitRacing.com

 

Thats a really nice setup, way cleaner than a lot i've seen. Nice job.

 

Ford used to sell a plug to delete the factory valving. i did mine many years ago so I am not sure if they still have them, but it is worth checking.

 

the whole stock brass piece from the factory is actually a combination valve that has a valve inside to slow down the front disc to catch up with the rear drums and the stock proportioning valve is in there to. so if you converted to rear disc you would need an adjustable proportioning valve and you wouldn't want to slow down the rear disc so just throw the stock one away. with that being said i don't have my stock one anymore and it works fine but i haven't put to many miles on it yet. i just used a tee for the front brakes.

 

To add a little to what was said above, i believe its best to remove the stock valve completly! A lot of guys are going to say remove whats inside it and put the solid brass cap on it, but i think they could be setting themselfs up for a bad accident. If you do that and a brake hose or line bursts you will completly loose your braking abilities because the 2 lines comming from the master cylinder now go into a common "union", or the stock proportioning valve that was gutted. I know some of you are thinking that a burst is uncommon, but in both my Mustang and truck its happend! Your best bet is to get rid of the stock valve completly.

Brake Proportioning Valve Eliminator kit, 1987-93 [MMBAK-6] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

The kit above is an easy way to remove it. If what i said above is wrong, please feel free to correct me.

 

If you cant find the plug to gut the stock unit you can do what 5mustang8 said.

 

I did the plug thing and have a manual adjusting valve, but want to clean it up more like slo895.0 did. So basically I just need to T the front ones together?

 

How i plan on doing it, which should be within the next couple of months, is i am going to remove the stock proportioning valve completly, put a union on the line closest to the front of the car, and then put a tee on the line just behind that one. The extra line that used to go to the master cylinder will now go into the rearward tee fitting. I hope that make sence. I will get pics when i do mine, but like i said its gonna be a few months away.

 

I went all MM. Easy as hell. 3-2 kit, prop valve eliminator kit, wilwood adjustable in the rear line. Gorgeous setup.

Don't reinvent the wheel.

--
Dan in ND
'89 'vert GT undergoing full resto.

 

On my 86, I wanted to retain the low-pressure sensor built into the stock prop valve (later cars have a low fluid sensor on M/C). So I gutted the prop valve per the SSBC instructions (they only had you remove the spring and plunger, but retain the tube and stock plug with the rubber center). Worked pretty well with the SSBC rear discs (same as the T/C/93 Cobra). The problem wasn't the gutted or manual prop valve; it was those completely mismatched 73mm SVO calipers. Anyway, ran it that way for 15 or so years until I swithced to the sn95 Cobra fronts (retained the SSBC rears) - better match. At that point, I replaced the stock prop valve plug with the FRPP piece - by the way, both MM (brass) and LMR (aluminum) are reproducing those plugs.