Wheels originally designed for disc brakes are built differently than our vintage truck wheels. If you look at the back side of your wheel, you'll see it steps down in diameter twice from the bead to where the center section welds to the rim. That second step will be smaller (larger diameter) or non-existent on a disc brake wheel. I was able to put disc brakes on my '46 with the original 16" wheels with the use of spacers and a little grinding of the caliper, about 1/16" off the crown. My kit was from a different vendor but the one shown online for yours looks very similar.
When I stepped down from a 17" rear wheel to a 16" on my Ram 1500, I also had to space the wheel out 3/4" and install longer studs. Even with some pretty vigorous grinding on the caliper, a 1/2" spacer just wasn't enough. I was compensating for a torque converter clutch that just refused to stay engaged unless I was running 75 MPH or so. Every time I'd tip in on the throttle, the converter clutch would disengage. Jerry
The murder victim was drowned in a bathtub full of Rice Krispies and milk. The coroner blamed the crime on a cereal killer!
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
I think I would have gone the plan B route if I didn't already take the original wheels to a shop to have the flat spots trued up. Keeping everything as original on the truck as I can with exception of the front brakes and master cylinder...Going to go with radial ply look-a-likes with tubes...
Today I got the air grinder out and quickly took some of the caliper corner back. I then took the other wheel's spacer off, and doubled it on the one I'm testing, and it looks like I'll be good.
So in short, if I use 1/2" worth of spacing on each wheel, along with some reduction on the proud corners of the calipers, it looks like I should end up with enough stud thread to work with. Off to NAPA tomorrow....thanks