master cylinder conversion confusion

Hi,
My setup is 68 with 4 drums (10 inch) and the single piston MC. I am slowly gathering parts for up grade to dual piston MC and disk brakes (very slowly $$).
I know I know call Herm for kit. The problem is I already have a brand new dual port MC with the exit ports on the passenger side, it is for 72-75 Cj all drums according to part# 8126737 courtesy of "thejeep.com". Now I read an article BS or not ?? that said 1968 and earlier MC have residual pressure valves inside and cannot be removed/changed. It also said that 1968 and newer have the residual press valves screwed into the exit ports and can be unscrewed/ changed. The 8126737 MC that I have does not appear to have anything screwed into the exit ports (I can insert a paper clip end all the way into the middle of the MC). Can I use this MC and just add an inline residual press. valve ? Can I absolutely not use this MC?? You know finding the right MC can be difficult- it has to have the ports on pass. side, be for disk brakes, have the right mounting, have the right size reservoirs, and big enough pistons.
What to do?

Josh

 

Update:
I was just reading thru Steve Lane's write-up on converting to disk brakes. On page 6 he has a picture of the MC he used and paragraph explanation. I swear my MC is the same as in his picture- exactly the same. My MC box indicates( handwritten) that it is a 8126737 which pans out as for 72-75 ( Mistake??). He says his is for 67-71 and that he removed the residual press. valve from the MC and put in an in-line valve. How do I do this??


Josh

 

Doesn't seem like you have the residual pressure valves in the MC. To mount them inline all you need to do is locate some and stick em in-line.

The two pound valve is used in disc brake applications where the master cylinder is mounted below the horizontal plane of the calipers and fluid drain back occurs from gravity and vibration, thereby causing excessive caliper piston retraction and a longer brake pedal stroke. The minimal two pound residual pressure prevents fluid from flowing back without causing the brakes to drag. With drum brakes, a ten pound valve is used to compensate for return spring tension in the drums. Residual Pressure Valves are made from billet aluminum and color coded for easy identification. Ideal for drag racing, street rod and many off road applications.

From:
http://www.wilwood.com/Products/006-MasterCylinders/010-RPV/index.asp

Hope this helps.

 

A lot of info here:
http://www.piratejack.net/troubleshooting/Main.html
Happy reading!

 

Thanks guys that info really helps especially the Wilwood info.