Firstly, the brake in the photo is a typical 46-48 with self-centering shoes; no
adjustable eccentric lower shoe anchors as with 39-42's. When I first looked at the photo, I immediately wondered about the wheel cylinder, as mentioned.
It is supposed to be a "step bore" with 1-3/8" forward piston (39-41's were originally 1-1/4" but those are no longer available new...) The rear piston is
1". In the photo, it appears to have the same size at both ends? On Ford/Lockheed brakes, the larger pistons face forward. The cylinders for the rear brakes are 1-1/8" forward and 1" rearward, which results in "front bias" so there is more braking force applied to the front brakes than the rears. These brakes are NOT self-energizing, and the stopping is mostly performed by the forward shoe when going forward. The rear shoe does very little except when going in reverse. Accordingly, they have "design" limitations...
Secondly, you apparently have more modern Bendix (self-energizing) brakes on the rear. Maybe you have a late rear axle??? Anyway, the Bendix brakes
stop WAY better than the Ford/Lockheed and with much less pedal force. Therefore, this improved design will be enough to create "rear bias" when used with the Ford Lockheed brakes on the front. This can result in the rear
brakes (where there is also less weight) locking up before the fronts, which can result in serious loss of control, like "swapping ends" depending on other factors. This is definitely NOT a good thing!!!
Suggestion: One way or another, you should install Bendix brakes also on the front. If you plan to run Ford or KH wire wheels, you will need to continue to use the 12" Ford hubs/drums, and with Wire Wheel Support Rings. You can either find a pair of Lincoln-Bendix brakes (1941 fronts = "hen's teeth and BIG $$$) or 39-48 rears, which have the same offset as the Ford/Lockheed brake plates. 39-40 fronts ("deep dished") which are also rare and $$$, can be used with original 32 front spindles by doing some other stuff AND using the Lincoln front hubs with either good original drums or new USA drums. The 42-48 Lincoln brakes are "medium dished" and can also be used, but there are some more issues to deal with AND wire wheels do not fit the drums. Another option is to use the new reproduction Bendix brakes (marketed as 39 but they are not) with Ford hubs and drums. These are available from myself and others.
IF you do not plan to use wire wheels, you can also use the 11" F-1/F-100 brakes. (Apparently wire wheels CAN be used with these, but a very thick spacer is required and that may mess up the front end geometry??? so I do not recommend it - others will disagree??? "Stand by".) Frankly, these smaller-diameter brakes also LOOK crappy as there is "too much empty wheel: as compared to the 12" brakes.
IF you have an original 32 frame with K-member and original pedals, a true
"bolt-in" (using only factory holes) master cylinder setup is available that uses the original/unmodified pedals (no whack and weld) does not require relocation of the battery, or any other permanent modifications.
