Here are the numbers for some of the Clark overdrive 5-speeds:
200VO (M) 6.06/3.50/1.91/1.00/0.80/4.87R
204VO (M) 6.06/3.50/1.80/1.00/0.80/6.00R
205VO (M) 6.06/3.50/1.91/1.00/0.80/6.00R
207VO (M) 6.06/3.50/1.80/1.00/0.86/6.00R
251VO (M) 6.06/3.50/1.80/1.00/0.80/6.00R
264VO (H) 6.06/3.50/1.80/1.00/0.80/6.00R
280VO (H) 5.98/3.50/1.86/1.00/0.80/5.04R
280VOHD (H)6.17/3.48/1.85/1.00/0.79/5.10R
300VO (H) 6.27/3.51/1.89/1.00/0.80/6.27R
380VO (H) 6.27/3.55/1.89/1.00/0.80/5.11R
400VO (H) 6.17/3.56/1.90/1.00/0.80/6.02R
The older ones, such as the 204VO and 207VO are unsynchronized, but the newer ones have at least 2-5 synchroed. They are all pretty much 4 + granny with 1st below reverse, but 1st is not nearly as low as 7.06:1 on the SM420. For regular driving you would shift it like a 4-speed, using 2nd through 5th. They also have a strange shift pattern, with 4th and 5th swapped.
As far as shifting speed, this Clark 280VOHD
[img]http://www.eskimo.com/~pparkin/truck/images/m_clark_280vo.jpg[/img]
that I'll be putting in my 1-ton has a suprisingly short throw; maybe 7 - 8" top to bottom.
All that being said, I agree that a better first step would be lower gears in the rear end.
