Thanks for the info - has anyone here used their original 32 hubs with the later drums/backing platesin a hyd brake conversion?
I had to to brake drum junk pile and look. 1932 drums and hubs were cast as one piece, there were no separator hubs, at least there is not on the pair of '32s I have. The drums are also too narrow to use the wider hydraulic shoes. The only mechanical brake drums that will work with hydraulic brakes are the 1935 rears. They are neat because they have the wire wheel hub support built right into them.
You will need an adapter kit for the hydraulic brakes to '32-'34 spindles. There are two versions. The original style looks like a piston ring and a valve insert. That's because that is exactly what they are. I broke a piston ring just sticking it into the backing plate because it was a snug fit. I guess I should have gaped the piston ring like i was sticking it in a cylinder. M/T brakes has a better setup. If your going to run wire wheels you will need another set of raptors also to support the wire wheel's hub on a hydraulic brake drum. They have those too.
The backing plate holes are 3/8" on the hydraulic brake and the ''32 used 5/16" bolts. There is not enough "meat" on the spindle to drill them out to 3/8". People do it but I don't like it. Its paper thin at the out edge of the hole. You would need to reduce the size of the backing plate holes by either using a special shoulder bolt, weld on some thick hardened 5/16" washers or weld up the holes and re-drill them to 5/16".
If you use the '39 to '48 spindles it will eliminate the need for the adapters and the backing plate hole size problem is solved. But then you loose the drag link arm on the original '32 spindle. Then you need to install the "hoop" style drag link attachment in place of the top backing plate bolts.
Another option is to get the reproduction Lincoln front brakes. You can order them with 5/16" holes so that solves one problem. That's what I did. Not the cheapest route to go. MT Car Products website.
http://www.mtcarproducts.com/productsgrid.html
Here are my thoughts on which spindles to use. If your updating the brakes on an original '32, I'd stay with the original spindles. If your building a 1940s style '32-'34 fenderless hot rod with hydraulic brakes. Look at the photos from that era and you will see almost all the '32s had their original spindles with the built in drag link arm, adopted to hydraulic brakes. I collect early hot rod photos, I have hundreds of them. If your building a 1950s style hot rod then you use the '39-'48 spindles with the bolt on drag link arm. I like the look of the round '39 to '42 spindles best instead of the '46 to '48 square spindles. I figure you have a round backing plate and a round wheel, might as well stay with the theme and go with the round spindle. They look a lot better than the square ones.