As some of you guys know, this past winter/spring I've spent a good deal of time working on my form and in the process shortened by DL by about an inch. So, I'm in the process of building some new hunting arrows and I'm running into problems with a low FOC and I need some help increasing it.

Bow Specs:
27 5/8" DL
70 lb DW

Current Arrows:

XX78 2315 @ 28.75"
100 gr points....Thunderheads or Muzzy
3 7/8" Duravanes (I think they are straight fletched or else just very slight offset)
Wrap
Total Arrow weight: 528 gr
~240 fps

OK, here is what I am thinking. I want to stick with the 2315s, but I can shorten them about an inch. (27.75"). I'm thinking going with a 125 grain head (Muzzy MX-4). I am wondering, can drop down to a shorter and stiffer vane, either 2" Blazer or 3" VaneTec, and still have enough stabilization for a big fixed blade head? If I put those vanes on either offset or helical, will that help? I shoot a Wisker Biscuit rest, does that impair any helical I use on the fletchings and ruin accuracy?

I think changing those things will improve my FOC, but I'm just not sure if those smaller, yet stiffer, fletchings will be able to stabilize my fat arrows and big heads. Does any one shoot something like this or have any recommendations?

Thanks,
Steven