thinking of getting a 4l60 to replace my powerglide, but don't want to use an electric speedo. the 2 speed sucks on the highway, but electric speedo's cost about twice of manual ones and I don't have a computer.

 

Early 3rd gens with 700-R4s (1983-1989) had cable speedos. The 4L60 is a 700-R4. Do you have a cable actuated speedometer, if so it should work ... you will just need to get the correct drive and driven gears for you axle ratio for the speedo to be accurate.