Muncie, Saginaw...lots of questions?

[shifty]

I'm tranny-ignorant. I'm shopping for a 4spd (floor shift) to drop in my truck right now.

I'm just wondering - Why the heck is a used Muncie 4spd five times as expensive as a used Saginaw 4spd? I've been looking at the M20/M21 Muncies and the 4spd Saginaws. Can someone fill me in on some history or at least give a brief overview? Is there really that much of a difference between the two?

Also - Aside from having an easier time shifting, what benefits will I see in swapping from 3spd on the column to 4spd on the floor? I mean, what will the extra tranny gear do for me in terms of gas mileage, top cruising speed, shifting points, ease of acceleration off the line, etc? I won't be changing my gear ratio in the ass-end, only the tranny. I don't know what my current gear ratio is either.

I always hear people say "sad old saginaw" over and over again here.

PS - not sure if this helps, but ... this is only going to be a temporary tranny until I can pay off the truck and drop an LT1 or LS1 + 6spd into it. Plan on doing this within 1-2 years.