The volvo's are slightly weaker than the mog 404 portals. I see consistant breakage at the Cal-Rocs comps of the 404 portals since the pot metal the portal housings are made from break from the side loading caused by the helical cut gears. This is with 40" tires or so. If you want to run 44's or bigger with no breakage you may want to look into some mog 406, 416, or U1300 portals. There pricey but they are ultimate beef. There rated quite a bit stronger than 2.5 ton rockwells as well and the portal gears are straight cut not helical so the side loading is not there. I have a set of 416's for the buggy and I can't get over how massive everything is in them /forums/images/graemlins/eek.gif