Someone else must have done what I'm trying to do here. I've searched this site, but haven't seen this brought up anywhere. I'm doing a complete brake upgrade on a 50 Chevy AD truck; disk conversion up front, a 12 bolt rear which may or may not get disks.
Here's my problem: My intention was to buy one of the many master cylinder upgrade kits, the kind that mounts in the original under-floor location, and uses the original pedal. I'm now just finding out that they all are 'for automatic trans only.' I, of course, am planning to go the manual transmission route. I called up 2 of the big name brake product suppliers, and asked about this. Both people said the same thing: since the clutch pedal is an integral part of the original pedal assembly, it 'won't work.'
I've looked at the photos of these upgrade kits, and looked at my old pedals. I don't see how the clutch pedal could interfere. Maybe it would become more obvious once I started the install, but it seems like it should work.
There has got to be a lot of AD truck owners out there that have done what I want to do. Hopefully one of you can shed a little light. Thanks.

First question, do you plan to run power brakes.

On my 48 that runs manual drum brakes we built a bracket that bolts to the original mc mounting holes and holds the dual mastercylinder. I have an adjustable rod running from the brake pedel to the cylinder. It is piece that was made from parts if the 48 linkage and the rod from the mastercylinder that I used and is reinforced . That setup has worked pretty well for over 30 thousand miles but will be swapped for a power unit for the 4 wheel disks that will go on in the rebuild of the truck.
I'd take a long hard look at their kit and attempt to figure out why it aledgedly won't fit a stick truck and see if I could figure a way around it.
If you can get to a major street rod event Like one of the big NSRA runs or a Goodguys show there are usually vendors there with the parts on sight so you can actually look at them and ask questions from the guys who build the parts. It's also nice to actually see and touch the parts before you spend hard earned cash on somthing that you have only seen a photo of in a catalog.
I looked at the ECI ec-505 and it looks like it should work if the shaft that the clutch and brake pivot on is long enough.
http://www.ecihotrodbrakes.com/mast...er_systems.html Scroll way down.
You might contact them and ask if it will work or if they will build a bracket that will. All it would take was to make the pivot shaft X amount longer.