offset difference in f100 vs. '40 hub

Im puting together a set of brakes for my roadster using f250 backing plates and buick drums. I wanted to use my f100 hubs with the bearing conversion, but the offset is way off with the f250 backing plates. I am running the hubs on the inside of the drum. Does the '40 style hub push the drum outward more than the f100 hub? What is the difference in offset between the two?

 

I can't tell you the difference in offset between the two but I can tell you that the '40 style hubs work with Buick drums and F2/F250 12" bendix style backing plates on 37-41 spindles. The OD of the '40 hub mounting flange gets turned to fit the flat mating surface inside the Buick drum; a hub to drum centering ring is created and the drum is redrilled to the 5x5.5 BP.

I know that others have used F1 hubs with the bearing conversion for the above brakes and spindles. I haven't tried it but I do know that F1 hubs and F100 hubs have different offsets as shown in this photo that I lifted from RICH B on this site;


It is interesting to note while F1 and F100 backing plates interchange, the hubs and drums interchange only as a set.

If anyone can measure any offset difference between a mounted '40 hub and a bearing-converted-and mounted F1 hub on the same spindle, I would love to know.

 

The inside mount '40 Ford type hub measures 3-1/8" from the face of the backing plate
flange on the spindle to the outside face on the hub.

The '48-'52 F-1 hub measures 3-7/32" from the face of the backing plate flange on the spindle to the outside face on the hub.

Didn't measure one; but the '53-'56 F-100 hubs would be about 1/2" closer.

Measurements were made with a straight edge and a steel rule, so they are not down to
the thousandth; but close enough for this kind of stuff.

Added a couple of pictures for reference.

 

Wow, in less than an hour! God, I love the HAMB. Sent Ryan another fifty last week, can't beat it.

RICH, thank you so much for that. ADReese, that should help you out too (didn't mean to jack your thread).

 

What would I do without the HAMB, its the encylopedia of traditional hot rodding! Thank you again for all of the great info!