Correction Our first attempt was 100 and 100 springs. We are now using 100 and 175 lb spring front and rear with a combined spring rate of 65lbs. The front weight is 350LB the rear is 600LB dead lode.
I think going from 100 to 250 (71lb spring rate) will be a little harsh of a spring rate change. We go from a 100 lb spring to a 175 spring ( 63 spring rate) with a primary spring stop on the shock. with the front only weighing 275 with rider per side a nominal spring rate of 50 lbs + is about right. The shocks we are using have a 12" travel using about 5" compression for ride height, wheel travel is about 14". Shock dampening is a big part of how the shock will work. Right now we have the shocks set up with very low damping in both directions. we are using a micro cellular bump stop of about 2.5 ". We don't jump the bug just riding over desert terrain. We still need to do more testing in large bumps. At this time the 12" woops are not a problem.