can you find a L50 or L52 over there?? they are full cast iron transmissions and have a 3.93 1st gear where the L43 you have has a 3.67 first gear.
and you have a four door cab 
Even though you've already broken into your L 43.
I in swapped mine for an L 52. And loved it. There's no Draw back. On either end of the spectrum
You get a lower first gear.
&
You get an over drive gear. (5th)
