<VV> High Alt YH Jetting?

[Grant Young]

HI. I am looking for some information for a carburetor customer for the best jetting
for a 1964 Spyder at 5000' above sea level, hoping for some anecdotal information. The
literature recommendations vary from no change needed until you reach 5000, to reduction 
of .01" for every 2000-2500, to .01 for every 5000, so I would like some real
life results if anyone has them for this particular engine and carb.
Thanks,
The Carbmeister