Dear Rusty:
A chunk of styrofoam, roughly cut and taped to the butt stock, can be helpful to get an idea of your length of pull. Same goes for taping something lke cardboard to the comb for a trial fit. Quick, cheap, and gives a good measurement to work from. We've all seen expensive guns on the range with...stuff...taped on the stock. Works fine till you get around to making things more more permanent. Woodbutcher