Thanks 3B. You are right regarding the front wheel bearing. The MPB separates the bearing in the cone, the inner race and the actual ball casings (please forgive me if I'm not using the appropriate words, my native language is Spanish, and my technial English is very rusty). Thats why I posted the 3 parts number for the same bearing. On the pinion bearings, the number 187434 is correct, but also there is a 7450438 for 1/2 ton trucks 1947-53 and 7450385 for the same tonnage for 55-60 H033 differential. Those are the number my parts book said. I´ll try the numbers you sent me. Thanks again
