take 1/2 the wires out of the front part of your small wire concave. set the sieves open, crank the fan and drop the concaves to about 12. Now you are ready for peas. I have only the front 1/3 of the concave with the wires out and hardly ever see a crack. I actually have a harvest services concave and cut the front wires out (they air hammer them in) and for cereals I just run a filler plate in the front. So I never even do anything with wires.
You have a year to get a straight cut header if you plan on growing them next year. That would be best. 971s are pretty cheap, and if you chose a decent standing variety you can get away with a non-flex head. I grow CDC Goldens and dad has DS admirals. They are both good standing peas and not a problem. Usually we leave 6 inches of stubble and still get all the pods.
we have 2 98's and love them in peas Andy's settings are same as ours. Another thing to do that really helps in rolling land is to remove the terrain tracer cylenders or the filler braces(if not equipped with terrain tracer) and put wheels or rollers on the rear corner of the header and let it ride on them this totally changes combining peas.just take care of the header hieght and it will float side to side on its own.