the l52 has a bigger input bearing. I was told that the l52 was from the 1983 trucks also. Funny because my 1981 toyota FSM has the l52 in it. weak point in both l50&l52 seems to be the overdrive. I'm running a l52 in my 79, it should be rebuilt, but it keeps on going 120+ miles every week, with lockers and bigger tires adding extra stress to it.