Ray,
It's not that simple and there's more to it than just the stock. Take a look
at your RIB and compare it to the rib on a legitimate TRAP gun. Since you own a Browning, let's use a BT-99 for comparison...
The rib on a Sporting, Skeet or Hunting gun is generally flat or parallel with the barrel. On a TRAP gun, the rib is higher near the receiver and it slopes down at the muzzle. The TRAP rib is designed to provide a higher Point of Impact. I'm sure you have seen or heard about 60/40, 70/30, 80/20 or even 100% Trap guns. What that refers to is the percent of the pattern that is OVER or HIGHER than where the gun was "pointed". There is a distinct advantage to using a true TRAP gun vs. a Sporting, Skeet or Field gun. The height of the comb and/or the design of the stock is just one part of the equation...
For what it is going to cost you to convert your gun to a trap gun, I suggest you purchase a good used BT-99 for now. Good, solid, reliable BT-99 models can be had for $750 to $1,000 and you will be able to sell the BT-99 for about the same as what you paid for it in a couple years.