Disc Drum Proportioning Valve 87' GN replacement

[GNONYX]

After doing a oil changed is when I started to smell like wire burning coming around underneath the powermaster.
I think my powermaster finally went after being the original one of having 90,000 miles.
I was thinking of also doing the vacuum replacement if it did go but now I don't have to think, now I have an additional winter work load of doing the replacement. I do have a spare powermaster unit, but after reading many stories of not having brakes, I'm switching over to vacuum.
I did notice looking underneath That I have the the original cast iron Disc Drum Proportioning Valve.
If I'm replacing over to vacuum type do you think I should also replace the Disc Drum Proportioning Valve with the new type of being made of brass?
Also I see many type of claiming to be equal as GM from USA made to China made
Has anyone replace the Disc Drum Proportioning Valve, and id so which one and what type was your replacement?
Thanks

 

[TexasT]

Kirban sells one. I think I bought mine off the eBay. It is also a brass one where the original is steel or iron. It was pretty crusty in addition to the rear brakes locking up. That is why I replaced it.

 

[Lockman]

GM recalled that very cast iron valve back in '91 or '92 ? There was a thread on here that I read a while back. I suggest that for the ~ 60 or so bucks , it would be good practice when upgrading one's Brakes. You never know when you need them to be there for you.
anything from Pirate Jack , Kirbin, Carolina Classic Trucks: IE, are most likely machined in America. Kirbin's is a great source & member. That is where I got mine from.

 

[GNONYX]

Thanks for the info I didn't know GM had a recalled
Will replace with the brass made in USA

 

[KC87]

The recall was for Canada only. IIrc about 1 out of 4 cars came with a brass one. Yeah, even with no salt driving the iron ones get pretty nasty. Did one a few years ago to brass and have to really tighten the fittings so be careful. Believe they all come from the same mfg now.