These are the Proline MT Baja Pro G8 tires. These are the BEST tires we have found for rocks. I used the supplied foam ( I ALWAYS cut the foam a bit but wanted to try with no mods.) and I cannot say there was a noticeable difference in climbing. We had broken in Baja Pros on it before and just went with new shoes. My understanding is that scuffed tires work best but could not see a disadvantage with the new tires. Personally, I have always thought a NEW tire with the sharp edges is going to hook up better. Both of the Capra's we run have a good amount of weight added and I would think the weight of a crawler has an effect on how well different foams perform.
I would like to hear if anyone has found an Amazon special (ok, cheap) tire that works as well as the Prolines and has a similar width.