swapped a disc rear end, still has the drum prop. valve...can i just take out the spring and plunger from the valve to make it 50/50 front to rear? i'm sure it's now 70/30 front to rear for disc/ drum. anybody done this or even heard about this? i just don't want to go through the pain of re-plumbing a new valve.

 

What year car do you have?
Edit: Ijust checked your profile, its says '83 Z28.

Use the 1LE(J65) propotioning valve Part # 14089496
Thread pitch is the same as your drum valve and will bolt right in. '89 and later have a different thread pitch. This valve will work on any 82-88 car.

 

thanks agood2.8...really? that's what freaks me out 'cause threads and line sizes vary by so much! just to make sure: it's a '83 z-28..has a brass prop. valve (not the machined aluminum ones later) ..rear line goes into the front of the valve..plunger access is on the bottom of the valve....i swapped a '86 rear.

 

Are you sure? I thought 82-83 cars had standard fittings and 84 and up went metric, with a change in size in mid-89.

 

this is confusing!

 

I sorry guys I should have been more clear- That valve will work on any pre89 car that has an existing square shaped aluminum proportioning valve -That looks the same shape (or style) as the #14089496 combo valve. it works as a direct replacement for any combo valve of that style.

Edit: Heck, I'll tell you what, I'll take a picture of mine so you can see what it looks like- If your stock valve doesn't have the same square shape then it won't work. Give me 5 mins.

 

prop/combo valve pic- 1LE (J65) combo valve for pre '89 cars.
GM lists two 1LE valves- one as pre'89 and the other as '89-92.

 

Sorry, I'll try this again with the right size picture