If you do that you might strip the threads. The posting (even in some service manuals) that say a 741 pinion nut should be torqued to 250 ft. lbs is incorrect. It's only a 5/8" thread so it only needs 150 ft. lbs. The newer 489 housing with the larger nut (and consequently larger threads) is the only one that needs 250 ft lbs torque. I also use loctite on them just to make sure they stay in place
