Belt length......Anyone?

OK, here's the deal.
I'm running a Ford 5.0 set-up passenger side mount Vortech YS.
I'm sidelineng the cogs (can anyone say belt tossing problem) in favor of the 10 rib 8" crank and 2.75" (maybe 2.50") blower pulleys.
Anyway I'm wondering if anyone else has made this change and ended up with this same pulley combo that I intend to run and if so,
what length belt in 10 rib are you using.
Brand names and part numbers as well as length would help a lot.
This inquiring mind needs to know before it goes nuts.
Car has already been in the garage for over 2 years because of the frustration of aforementioned belt toss problem.
Oh yeah, I've done the stainless steel 1/2 in. mounting brackets and the dual idler pulleys and the stainless tentioner plate and the braces and the different cog pulley combinations,
Belt after belt after belt after.......well you get the picture.
If someone is willing to share this info, you might be saving a life (mine):).
Thanks in advance.