Okay, I got to put some miles on the 4sp OD this weekend. Remember my cars is a 440, 4sp, 4:10 Dana.
The drivability is awesome, cruising down the freeway at 65 MPH at 2300 rpm.
Slow down to 55 and you can down shift to third (1:1) and the RPMs jump to around 3000 and the acceleration is quick and steady. I shifted back to forth at 5500, the RPMs dropped back down to around 3300 at 80 plus mph.
The overall gear spread is great, 1st is a tad taller than stock, 2nd is even a little taller (before I had to get into 3rd rather quickly to keep the revs down, around town I can now stay in 3rd and only need to shift into 4th when I get above 45 mph.