I gave the 58/60" a little more reflex when I designed it, so you would need to be cautious adding too much.
I gave one to the IL Bowhunters in 58" and it did 190 fps with 9 gpp so it is already pretty good.
If you mean the riser , yes you could do that no prob.
I ordered a decibel meter a minute ago, so I can get a real reading on the difference if any in the 2 designs. Now I gotta get a 10 gpp arrow for the new one. It won't shoot the arrows from the old design without going from 200 down to 125 grain points, and still slightly weak. This makes for a very fast arrow but increases the noise.
To get apples to apples , I gotta have 10 gpp for both bows....