Why is there some Z28's with 3908326 Rear Proportioning Valves and Some without

[dannystarr]

Hey Blackout Steve, I was just talking about the Z28 of the first Generation. But I think it would be great if we could have every first gen Camaro chime in. Cause we know alot of big blocks were supposed to have them and many others. I am sure this thread will die off long before we have the info we need. But a guy could dream I guess.........Danny

[BlackoutSteve]

Sorry, I guess I forgot the title of the thread was asking about Z28s in particular.

However, aren't the results of SS/L48s just as consistantly inconsistant?

[dannystarr]

Hey Steve, I can't tell ya anything about any other Camaro's. Only Z/28's and not past 1969. Any info is of course useful. But I sure would like to be able to have someone contact all registered owners of first Gen Z/28's and ask about the valve. Got a good start here I guess.......Danny

[Camaro Billy]

I'll chime in.
1969 SS/L48    11D (1968) build date
Has the valve. 275-8 date code on valve. Oct. 1st 1968
Billy

[LB68SS350]

 '68 SS350 (L48)  w/12bolt and no AC   03D build date    Has the valve   Larry

[westonz28]

Ok heres mine. 1967 RS 327 L30/M20 with the valve, 1968 SS/BB with valve, 1968 coupe 327 210hp no valve, 1969 LM1/350 auto with valve. Only one of them is an SS Camaro. Hope this helps.

[sam]

1969 Z/28 (11D-1968) has no valve. Still has original brakes lines.

[tinman75]

Have a 68 NOR built 10D car. L48 rs-ss, P/S, Non power drum brakes, 12 bolt  and no A/C and it HAS the valve. I believe it is stamped 285-67 or something like that, I would have to look.

[KurtS]

My 02E Z28 from the LOS plant has it,I think it dates about 54 days before the car was built.

I just stopped by and looked in the garage for you.                          Well, in the db actually.....
It's dated 038 8, so about a month ahead.

[69 skunk]

My 06A x77 car has the valve. Stamp is 108-9

[Dave69x33]

My Norwood 05A Z28 has the valve, date stamped 108-9, or April 8th, 1969. 

I was going to post a question to confirm the date coding on these valves, but it appears from this discussion that they are stamped with a Julian date code.

The valve is also stamped "KH" and "R" (see picture attached).  I assume the “R” indicated the rear or outlet side of the valve; however, the tab and hole in the bracket position the valve in one position.

Does anyone know that the “KH” stamp indicates?  Is this the manufacturer?

[KurtS]

Kelsey Hayes.

[dannystarr]

Hey Dave thanx for the info. Look's like we are on our way to gett'in some more good info. And as Kurt mentioned I also believe it is Kelsey Hayes that made them. And I am assuming also that the little "R" does stand for rear. The bolt's that hold them down are a different story. They are specific and as far as I can tell not your basic fender or common body bolt. There was I think 3 manufactures of bolts. But not sure about the one that made the bolt that held these valves to the frame. Maybe somebody else knows for sure. But lets not get off track. Still need people to chime in on their cars and these dang valves. Over and out for now.......Danny

[Pex68]

68SS 12D LOS L35 HAS valve 283-7 date.

Danny, could you post or PM me the info on the bolts?  I'm not sure if I put the right one back in there.  Has RBW headmark with 3 lines and star lock washer.  Haven't looked to see if this info was in your original post or not.
Thanks!

[Dave69x33]

The bracket on the valve on my car did not have witness marks that a lock or toothed style washer was ever used.  This is not to say that a lock or tooth washer was NEVER used.  However, based on page 302 in the ’69 AIM covering the L48 pressure regulator valve, it calls for a #3958062 screw with no washer called out.  Using AMK Products catalog as a guide, I used the 8062 screw shown in my pic to attach the valve. 

There where often several suppliers for a common used hardware.  The 8062 screw is called out for 6 – 7 various applications in the ’69 AIM (brake and fuel line clips, etc., to mention a few) so we can expect some variation on the manufacturer’s bolt head markings.