The main issue is collet height with the Windsor ones. 302, 351, 5.0efi, there are a lot of minor variations. There are a number of different lengths and types.
The best bet is the Dynoed250-style 2.05" intakes, cut down to 1.96". The exhast ones are best off left as they come on an XF. The 2V exhast valves on a Clevo are 1.65", so they should cut down okay.
The Chevy 350 valves come with taller valve lenghts. Measure your stock Intake and exhast valve length, then cross check for Chevy ones. I looked at 305 Chevy ones for my project 221 x-flow, but most valves are too short. The 350 have a much better selection.
The X-flow valves are tall, and you should never go shorter. All canted valve Fords (x-flow, Lima big block, Clevo, 351M, 400) have heavy valve gear, and everything has to be perfect.