I had the best luck with NAPA, they have these weird things called "books",... wink
Anyway, if I recall right I measured the bore on my the master cylinder and we found it was the same as the 1-ton trucks and they had one for me in a day. Wheel slaves depended on the truck, since mine was modified for a dump the fronts were 7/8" and I have two 2" slaves per wheel out back. I took the measurements in and they used a book to match them to later year products that were identical or at least close enough to work.

1956 GMC 370 dump " 'Tater "
1970 VW Volksrod "the Black Bomber"
2007 Chevy Avalanche
2020 Jeep Cherokee Trailhawk,
2005 Harley Davidson FLHTCUI

I dig all cars, old and new, whether they were hammered out of American iron, German steel, or Japanese tin cans. Being unable to appreciate them all is missing out on a world of great things.
But thats just MY opinion! :P