Ran Spicer non grease-able u joints in my rock crawler that was also street driven. 60 was built by Solid Axle Industries , 35 spline shafts, arb, drive flanges etc. I ran up to 37's in this jeep that saw amateur and professional rock crawling comps. I put probably 40K + miles on that jeep, both on the street and in hard comp running 37" Goodyear MTR's filled with water to the axle line during the comps. . Those u joints were the only ones to hold up to the abuse until I replaced them in the last 1000 miles I owned the jeep with CTM's.