Disc spindle vs drum soindle

Depends on the year however. I believe that from 65-67 they were the same spindle. At least that is what I've been told. From 68 on out there were different.


correct, the 65-67 had a special bracket that bolted to the spindle to "adapt" the calipers which works fine for a fixed caliper. 68-up disc spindles are specifically designed for a floating caliper and the attachment point was designed specifically for that purpose.
 
no. the 68-up disc brakes use a totally different spindle. if you're going to use a stock style disc system on your drum spindles you'll need the 67 style disc brakes. the SSBC kits are based on the 65-67 style discs. 67 are slightly different than the 65-66 but use the same style caliper. the fluid transfer lines are bigger on the 67 and the pistons are a little shorter.

the best setup for your car using the drum brake spindles would be the 67 disc brakes.