I’m looking to add front discs to my 71 but a lot of the kits I’m seeing add to the track width. I just ordered 18x8.5” wheels with 245/45ZR18’s, currently I have 15x7” with 245/60R15’s & have plenty of room with drums. There’s probably no issues with using a typical kit that adds 7/8” but just to be safe I’d prefer to avoid that if possible. Also, I’ve seen kits that utilize the factory drum spindle but can’t seem to find one while searching recently, are these types of kits worth it or should I go for the full spindle type?
I put Wilwood disc conversion on both my 1964 and 1968 Skylarks. The offset increase was less than a 1/4 inch positive. The only thing I had to do on 1968 was have the machine shop drill and tap the top "pin" bolt hole to accept the 5/8-18 countersunk bolt for the caliper mounts. (I pulled the spindles and took them to the machinist since trying to get a square boring and proper tapping would be a real challenge with the spindles mounted and I do not have a drill press). The cost of having the machinist do them vs cost of the drill bit and tap was worth the effort. On the '64, I used newer drop spindles and they were already tapped to the correct size.
Go with a disc set up off a 70 skylark. That’s what I used and could still use my 14” wheels. No offset, parts at autozone also.
I started out that way but by the time I added up the cost of spindles, rotors, bearings, hoses & calipers without cores I was over the price of the typical kit. Not worth it unless you can find a used set up in decent condition.
I was lucky enough to source a compete swap out. I really think keeping it GM makes parts easier to get when needed.