I had a L43 when i first got my truck, and ran it for about 10 years, it had no overdrive, and the 1st gear in it was higher than the L45,50 or 52.
the L45 and L50 are identical as far as bearings go but obviously one has an overdrive. honestly, all three of the later l series have a beefy housing and would work fine in most daily drivers and trail rigs
personally i rarely use my 5th gear in my L52HD and i'm running 35's and 529's about the only time i use 5th is on the interstate
