Trying to decide between width and length

[Bayou Ben]

This is how I do it.  My length is determined by how much working limb I want.  If I feel my working limb was sufficient and I got set on a bow, then I will make the next one wider, not longer. 
In your case DC, I would make your bow wider, maybe .25”.  I like to go a little wider than I need anyway, as you can always side tiller if you aren’t getting set.  It’s a little harder to reduce length. 
I think your bows have sufficient working limb for your draw and draw weight.  I would make them wider.  Just how I would do it.  Obviously more length could do it too. 

[bradsmith2010]

Bayou that sounds like a good plan,, could I add,,
shoot the bow at the over built width,, through chrono,, you can see its a bit slow cause the speed,,,
now leave the bow braced for four hours at a time,, so it settles in,, without shooting it much,, a gentle approach to getting the wood to stablize,,you will see the tiller change when you unstring, and can adjust accordingly,,,if it starts to take set,, you need more bow,,
side tiller the bow down a bit and shoot it through the chrono,,till you start to get the speed you think it should do,,
at that point,, you know about how wide to make to bow and how much mass that bow has,,( hopefully leaving it braced will have made the bow stable and it wont loose much when shooting,,)
if for some reason,, after the side tillering its still slow,, then it is probaby a bit to long,,
there will be a point of diminishing return,, where when you  side tiller the speed wont increase,, you know you are past your sweet spot for that design,,

[DC]

shoot the bow at the over built width,, through chrono

Should it be a little over target weight here? If I have to side tiller it's going to lose some.

[bradsmith2010]

yes,, but I didnt know you had a target weight,,,but I think that is a good idea,,cause then you would have to do some fixing if you go under too much, ,,,,mabe if you had some flexibility,, on the target weight,you could dial it in closer on the next bow,,

[bradsmith2010]

for example,, you shoot it at 50#,, its shooting 160 fps with 500 grain arrow,,
you side tiller to 45# now its shooting 450 grain 165
now you side tiller to 40# and its shooting 170 plus,,with 400 grain arrow,,
you go to 35# and still 170 plus with 350 grain arrow,,

the best mass for the poundage was about 40#,,,on your next bow you could design for a heavier bow,,
or as suggested you could start a bit high of a target weight,,

the closer you start to the sweet spot ,,, I think the less set the bow will take,, I have heard different thoughts on this,, but after shooting it at the 50# weight, if may have taken a bit of 50# set,, and starting closer 40 #   with that design would stress the wood less,,,?

[DC]

I can't pull much more than 40# so when I started this speed quest I made that my goal.

[backtowood B2W]

I worked on some ash bows. And tried different cross sections. I found out that this influence the amount of set too! T he one with the narrow back and wide belly, took less set.
But I guess this is very wood specific
Bttw