Brake Pedal ratio

[66_k10_manny]

How can I tell what brake pedal ratio my truck has?

[ERASER5]

You will have to calculate the ratio from measurements if you want to be sure.

Does your 66 brake pedal have one hole or two? 67 -72s have only one hole. A single straight rod to MC is the proper ratio for non-power brakes. For power brakes, the 67-72s use a linkage setup between the fire wall and booster. The linkage reduces the pedal ratio.

Here is a linc to Master Power Brakes. Lots of info here.

http://www.mpbrakes.com/uploads/docu...alratiopdf.pdf

[66_k10_manny]

Thanks for the info Eraser. I was able to measure and calculate I have a 6:1 ratio. And it only has one hole.

[ERASER5]

Sounds exactly right. While there is room to drill another hole to adjust the ratio, the rod would be at an angle instead of straight. GM used the reducing linkage to reset both the ratio and the angle.

There are several places to get the whole MC/Booster/Stand offs/ linkage as a unit new. Early classic, CPP, also check site vendors. Of course, there is the junk yard, but I never found one. Some of the guys that part out trucks have them from time to time. If you can get just the stand offs and linkage, the booster and MC are still stock items at most any auto parts store.

But you may already know all this, being as you even knew what pedal ratio was. Most have no idea.