Hey guys, I'm getting ready to finish out the instal of my 65 Chevy G10 van axle in the 61 Falcon Gasser and have a question about converting to disc brakes (already have discs on the quickchange rear out back). I searched on the Vintage Vans forums and saw the disc conversions that people used, but they are all swaps to a front rotor that replaces the existing front drum hub. My questionf rom a technical standpoint is this: Assuming i get the spacing/offsets/etc correct to mount the caliper, is there anything technically wrong with using the common '78-80 Trans Am REAR disc "hat" and putting it over the the stock front drum hub. I know i'd have to knock out the lug studs and file the hub surface flat for the rotor to sit on. The rear TA rotor hat would sit on the hub exactly as the stock drum sat on the hub. I could then just make my own caliper mount that bolts to the back of the spindle just like the other kits have. Thanks, -rick.
Thanks! I figured i was ok, but lately noticed no one on the other sites seems to do it that way (but the other sites aren't really into fabrication by the owners, so that's probably why they rely on someone else's kit). I will probably need to have a locator ring machined that matches the od of the hub and ID of the rotor hat for proper indexing. -that shouldn't be a problem to have a slip fit ring in the mix should it? -rick
Usually the rear discs are lighter than front discs- as they do not have to do as much work on the back. Many of the 4 wheel drive trucks used a similar hat style rotor- might be a better choice as they have more meat to them.
Don't know if this helps you but I used a 51 chevy car hub with the spindel and a 1969 pontiac trans am rear disc brake rotor,...the hub had to be turn down a little so the center hole of the rotor would fit snug onto the hub,..the lugs had to be changed to longer ones........ miller
the only difference between the unicasts an the rotor itself are the thickness of the rotor across the faces , in a lighter car it should'nt be a factor , just make sure you do not over heat them , if you want a larger rotor 11.5 vs 10.5 , what guys do is cut the hub to the interal dia of a late 80s F-body 1le option rotor as its made for competition and LEO usage but you have to check the internal clearances of the calipers on a 15" rim and 14" rims will not work at all .
Might also look at the S10 rotors from around '84-'87. They are a separate rotor from the hub and may work for your scenario without much fitting.
I think you would be fine. The diameter is the same as many cars with discs in the 70s/80s, 10.5" or 11" What caliper were you planning on using? I have always wondered how people fab up brackets for GM calipers, arent they are an odd thread size? I had been planning something like this in my head for a while, Miller mentioned the disc fitting the stock chevy hub. I was thinking of using a caliper with a fixed mounting "cage" to make mounting easier
I'm going to use the gm metric calipers. They're small and cheap. Speedway has universal caliper brackets and list the specs online. I don't remember any oddities about the thread pitch. I'll probably buy a set then add a homemade portion that has my spindle bolt pattern and correct offset needed. -rick
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