Better late than never....
203 vs. 300... ...BOTH!
Below is my NP435 trans with an NP203 (low range gearbox) in a Chevy variety, flipped upside down, with a 23 spl Dodge input gear in it... with Dana 300 bringing up the rear...
(T-150 looks sooooo small next to this)
By the way, if I had to do it over, I'd have bought a STaK... but the doubler should provide me with hours of shifting entertainment...