Here's what I found. Apparently the first 2500 trucks in '54 used 1" wheel cylinders and then switched to the 7/8" cylinders that you have. This is from the March 57 Parts and Accessories Catalog.
Based on that, I think you'd be fine with 7/8" diameter wheel cylinders. Or with 1" cylinders if that's all you can find. There's a note saying that at the bottom that listing.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
