according to gm part wiki
the USA version of your truck would use
5454314 (cast number 5454251) 1.5 inch wheel cylinder - two mounting holes
dorman W18197 crosses to that GM part
amazon.ca has them
https://www.amazon.ca/Dorman-W18197-Wheel-Cylinder/dp/B001PYTQGEi suggest you remove the one from your truck and measure it and if it is indeed 1.5 inch, and looks like the photos on Amazon, then go for it
also, could try walking into Napa with the old one as see what they can do, but i doubt they will be cheaper than an online search
take note of that "note 1" detail from the parts manual
if you have material mismatched from old to new, you can clean up and reuse your original pistons in the new cylinder from wherever
example:
if your truck has steel pistons, but the replacement uses aluminum pistons, i would de-rust and reuse your steel pistons in the new cylinder
-s
