Knew where you bobs409 were going, soon as "You finally got the fence on your band saw set to a perfect 90", though probably meant stationary jaw. While most pivot frame horizontals are similar in design, I don't recall any index pins for 90. Obviously, manufacturers don't like setting it either.
Angle blocks are the best solution.

I'd add one detail; slotting two faces length-wise *10 or 1/4" for adjustable stop. Handy again when it returns to weld bench...