The engine will make basically the same peak power with either the 3.79 or 4.00 crank but the power curve will be different. The 4.0 crank will move the torque peak down a little bit. PipeMax will give you enough numbers to make some decisions.

If you have an existing chassis then you might use that to make a decision. It can get expensive if you have to change gears, tires, transmission, etc. for the new torque peak.

For bracket racing the longer stroke is usually a good idea since it lowers the engine speed which allows the use of less expensive parts for the valvtrain.