Some D60s have 1310 pinion u-joint, like mine right now, but upgradeable to 1350. If you're looking for the upgrade get a Dodge 2500 front driveshaft from a 2005-up truck. Not sure what the upper limit is on years, that's just what I heard. They have 35+ degree running angle of the double cardan joint, and 1350 u-joints throughout.
To be able to go with Jeremy's driveshaft you need a front output yoke from a 73-77 (maybe 73-76) truck. This is what I'm running now. You could use this front yoke...
http://www.dennysdriveshaft.com/p1307_cv_yoke_1310_series_10_spline_for_np205_front_output.html
...IF you have a 10-spline front output, which I dont think you do. I think 203s have 10 splines, 205s have 27 splines, you should count them to be sure. I went with the F*rd 32 spline front output shaft mod for NP205 so I could run rear yokes on the front. It opens up your options to 1350 and 1410 if you want to run much larger u-joints. Just have to swap in a rear yoke seal in the front to make it work.