dual master cylinder upgrade

[mrbuick65]

Hi Guys. I am attempting to add a dual reservoir master cylinder on my 65 GS. It has power drum brakes which I want to maintain. The 67 Skylark cylinder I purchase has only a dimple where the push rod is to hit and the single master has a deep hole. Obviously I need a shorter rod. The booster is I believe Bendix and has a funkey looking pushrod with a threaded lengh adjuster for fine tuning and a large diameter at the boooster end. The length is 4.1 and needs to be about 2 5/8. It`s not just a matter of cutting to this length. I do not want to change the booster as it works perfectly. Any suggestions?
John

[Loren At 65GS]

John,
  Check out Inline Tube. They should have what you need to do the change. There are two different master cylinders, as you have found out. A deep well and a shallow well. Also you will need a different distribution block.

  Loren

[mrbuick65]

I`m probably going to purchase a delco booster as you can get 2 lengths of pins. I`m not keen on cutting and modifying the bendix pin and it`s a used booster at this point anyway. As for the distrbution block the original can be used. A mechanic friend did the conversion on a 64 Beaumont(Delco booster power drum brakes) He simply removed the rear line from the distribution block, connected the rear line from the master using a coupling. Now this port is open and the front master line goes to it. The original front port in the block now is open and it gets blocked shut with a plug. He did get fittings for the 2 master line holes to accomodate 3/16 lines. It`s been like this for a couple of years now and no problem.
John

[WkillGS]

.....
As for the distrbution block the original can be used.
... removed the rear line from the distribution block, connected the rear line from the master using a coupling.
John

I've used that method as well. Simple, and it works.
GM used a larger 3/16" line front-to-rear starting in '67. The 64-66 is a 1/4". The 1/4" line will suffice, but it makes finding the correct adapters difficult.