Bill,
Glad to see ya posting. I was wondering if my novella length email scared ya off
First things first...
With the amount of reflex on a Bowtech, and assuming and arrowrest like Golden Premier or other rest that sits back a tad, I suspect you most likely will end up with an arrow closer to 29" if not under a bit. Assuming the use of vanes on the back end of it, and a string loop, and 125 grain points a 3-60 should suit you fine for any of the model choices you are contemplating .
If you decide on a dual cam and WANT to shoot a 30" + arrow or feathers w/ a 125 grain point, I believe the 3-71 would be the wiser decision if you must buy a dozen beforehand and you are entirely set on a dual cam.
If you end up w/ the ExVFT or a Patriot SC, the 3-60 may still be your best bet. it depends on exact poundage, cut length, and fletching type again though. Many variables.
Arthur put it best
Problem is, when it' s that close it' s hard to make a decision just based strictly on the charts. Trial and error is the only way to really decide but, in the case of ACC' s, error can be expensive.
I would highly suggest you pick your bow, and throw some of the ICSH 340' s you mentioned in your email through it and see what happens. They are a little softer spined than a A/C/C 3-60 and may guide you to the correct spine choice very quickly (shoot groups...don' t rely on paper)
Fire away if you have any more questions