Pappy...I just finished attempting to replace the idler pulley bearing on my '90. It turns out that I had the '85 type pulley on there with the larger bearing and retainer clip although I had the correct size 14mm nut holding it on. Since I bought the 6203 bearing it was too small so I pried the seal off and repacked the old one as suggested by 94krawler. So far it works fine. Unless the previous owner swapped it out for some reason which I doubt, Im pretty sure this was the original pulley for this truck and am curious if anyone else has this type pulley on a newer truck?