Well I think it also depends on what impedance your pickups are.
I had to change the pots on my modified JCS because they didn't match the Gibson Lo-Z pickup I put in.
I believe the JCS had 250 K Ohm pots installed. That didn't work with the Gibson Lo-Z pickup.
But now I have 2.5 K Ohms (Yes that's correct: 2.5 K) like it says in the wiring diagrams from the Les Paul Bass / Triumph.
It wasn't easy to find them by the way...
I've been looking for 2.5K Triumph pots, Rob where'd you find them? Actually, I think I'm still trying to figure out what taper the original ones were. Do you know or did you just assume audio/log (some schematics show linear for some pots, log for others, and sometimes even a 3rd marking that I'm not familiar with - there are more than 2 pot tapers available).
And Yes, Rob, Hi vs Lo Z will change things significantly, but one HiZ pup vs another, is not that much diff (the Z is in the same ballpark) - the reason that they recomend 250K's for single coils is because they're usually too trebly (a matter of taste, some people love that skewed tone, which is why no-load pots and wiring straight to the jack are popular mods). Humbuckers have double the inductance which acts as a low pass filter (just like a 1st over crossover on a woofer in a speaker cabinet), that's why buckers are darker than single coils (exception being great big hoinkin granddaddy coils like the original EB pup which have heela inductance as well - basically the more and/or thicker wire around more magnet = more inductance = less treble). 500K's are used on buckers to preserve what treble they do have; 250s are used to tame the treble on singles so they sound fuller (as per DrBassman's fancy).