Take it that you have given enough time for the butt to harden but saddle fit is critical. First of all is saddle width and the buttometer at Specialised dealers can help on this. Wide comfy saddles are fine for a few miles but in general a firmer saddle is required. Not the rock hard ones but just a bit of cuchioning by foam or gel as in the Flite Gel Max saddles do help.

Next is saddle position in relation to height and fore and aft. This does take a bit of adjustment to get right and a friendly LBS to advise will help.

Then there is saddle tilt. I normally start with the saddle level to the ground and adjust from there. I like to get it so that I am taking the weight on the sit bones which should be on the wings of the saddle. Then adjust tilt so that I can just feel the saddle on the pubic bone. Then ride. If It still hurts the pubic bone then tilt the nose downwards. If I am sliding forward on the saddle them adjust the nose upwards.

Can take a fair time to get right but if the butt cannot get comfortable then it is down to trying new saddles---In the plural. For some of us it takes a long time to find the comfy saddle for a 100 miler.