In about two or three weeks i am going to swap my 10 bolt open for a 9 bolt posi disc rear.

I was woundering what will happen if i dont change the proportioning valve and just leave the stock drum valve.

Yesturday i went to a place that they only sell f-body parts, and asked for a proportioning valve for the swap i want to do and they told me that i would need to get a 82-84 proportioning valve that came of a car with disc. Becouse the threads on the newer cars were different.

Can anyone give me some advice, or help me with this little problem i have. -Eric

 

If you don't change the valve, the rear brakes either come in too hard or too soft, I don't recall which but, it don't work proper.

for the aggrivation of having to bleed brakes, might as well do it right the first time, you know what I mean.

 

You need to avoid the pre-'84 valves because they have SAE fittings. You need metric fittings.

 

wrong.

it works fine.

its not ideal, but it does work good and is far better then stock.

if you do decide to change them, you need a 85-92 4 wheel disc valve.. the earlier ones have a diffrent thread then your 90.

 

So you are telling me that if i stay with the stock proportioning valve it will work?

Any ways the drums really dont do too much work.

-Eric

 

yes they work.
yes they stop better then the stock drums.

however, they wont stop as fast as they potentially could with a diffrent prop valve. how much of a diff vs the stock Disc/Disc valve? not much. how much vs a aftermarket adjustible... more then enough to justify the cost and time of installation.. in my opinion.

what i would do (or i should say, what i did do) is drive with the stock disc/drum prop valve, and on your next full brake service, put in a new aftermarket wilwood valve. also when you do that, its a good time to put in new flex lines, stainless or factory replacement, doesnt matter.

 

I got a new prop valve for my 90 formula for my LS1 front/rear disk swap. The GM PART # 10164112 Late 89 to 92 valve 1.5M .

cost me about $65 shipped New.

 

Now hang on, I'm not here to **** and moan but how can you tell me I'm wrong. the only thing you've done is said that yes it comes in a little harder/better. All you have done is eliminate where I was confused.

Don't say I'm blatently wrong when you are clarifing my comment. That's just plain rude and ignorant.

 

that statement is wrong.

they work properly. fine. correctly. safely. however you want to phrase it.

so, i said:

wrong. it works fine.


doesnt seem rude or arrogent to me. it works properly


i apologize if it came off as rude, i was just correcting that last statement.