My 5-speed is from back when they sold them FOR AMC:
Richmond Gear(DNE) 5-speed, 21.57" length, short version.
1-1/16"-10 spline input shaft (Ford shaft), 10.5" clutch.
3.28, 2.13, 1.57, 1.24, 1.0 ratios.
GM Turbo 400 slip yoke.

Here's what they have now (just different input shaft):

PartNum. App A Dim B Dim. C Dia. D Dia. E Dim. F Dim. G Spline
7021710 GM 6.66 1.06 .590 4.683 21.57 3.22 1-1/8-26

1st 2nd 3rd 4th 5th Rev. Torque
3.28 2.13 1.57 1.24 1.00 4.79 450 Ft. Lbs.

http://www.sallee-chevrolet.com/Richmond/Street_5_Speed.html

The Richmond 6-speed for GM will swap rite in to a 5-speed equipped car.

Here's the 6-speed data:

App A Dim B Dim. C Dia. D Dia. E Dim. F Dim. G Spline H Dim. J Dim.
GM_ 6.66 1.06 .590 4.683 21.57 3.22 1 1/8-26 20.75 2.00

P/N____Input shaft1st_ 2nd_3rd_ 4th_ 5th_6th_ Rev. Torque
7021626AA 1-1/8‚Äù-26 Spl_3.28 2.14 1.57 1.24 1.0 .76_4.79__450 Ft. Lbs.
7021626AK 1 1/8‚Äù-26 Spl 3.28 2.14 1.57 1.24 1.00 0.80 4.79 450 Ft. Lbs.
(Special Heavy Duty 9 DP Road Race 6th Gear Sets)
7021626DD 1-1/8‚Äù-26 Spl_3.01 1.88 1.46 1.18 1.00 0.62 4.79 450 Ft. Lbs.
7021626ED_1-1/8‚Äù-26 Spl 2.77 1.88 1.46 1.18 1.00 0.62 4.79 450 Ft. Lbs.
7021626EL_1-1/8‚Äù-26 Spl 2.77 1.88 1.46 1.18 1.00 0.84 4.79 450 Ft. Lbs
(Special Heavy Duty 9 DP Road Race 6th Gear Sets)

http://www.sallee-chevrolet.com/Richmond/6_Speed_ROD.html