The Stovebolt Site Forums The Parking Lot Big Bolts GMC 4000 top speed

Couldn't find anything on an NP540 with a GL suffix. However I found a couple references that say the '57-'69 NP541GL transmission should have the following ratios:
1st 7.24
2nd 3.88
3rd 2.19
4th 1.37
5th 1.00
7.22:1 R&P

Oh, and if anyone wants it, and ya have Microsoft Excel, I can email ya my engine/transmission calulator.
Allows you to figure exact displacement (numbers are plugged in as mm’s but gives results in Metric and SAE), compression ratios, & camshaft data. On the 2nd tab, it gives speeds according to tire diameter, R&P ratio, gear ratios up to 5 gears. You just plug in your shift RPM/redline for each gear and it will give you your top speed for each as well as the approximate RPM at bottom of next higher gear. I made it for building engines & figuring gears for drag racing to keep the engine in the top of the torque curve. Still pretty handy for fun questions like these.