What can be said about the 4-speed New Process NV833 overdrive manual transmission?

[Dazzoman]

Originally Posted by hatzie

I ran a 1985 305 with an SM465 and 2.73:1 rear gears. She ran around 11-12mpg in town and 14-15mpg highway. She was a dog too.

If you're after highway mileage I'd lean toward the A833 with shorter rear gears like the 4.11:1 set. That was a very common ratio so you may already have them.

The original 1966 pickup truck axle came with 3.07:1, 3.73:1, and 4.11:1 gears The ElCamino could be had with 3.36:1 gears. 4.11:1 was listed as "overdrive only" the taller, lower number, ratios were used with regular gearboxes.

GM New Process A833 NP440 MY6 MM7 overdrive transmission ratios.
1st 3.09 2nd 1.67 3rd 1.00 4th 0.73

Assuming you are running metric tires close to the original 1966 C10 size 205/75R15 tires.
You can shift MPH to RPMs by several hundred RPMs just by changing tire sizes.

65mph in 0.73:1 4th gear 205/75R15 tires and 4.11:1 gears would be turning roughly 2400 RPM.
Launching might be a bit more difficult. 5MPH is 787 RPM...

You can do a bunch of what-if calculations in my spreadsheet.
The red numbers are transmission ratios. For 5th & 6th gears just enter 0.00 The RPM to MPH tables will re-calculate when you change the red and blue numbers.
The blue numbers can be edited for tire size and other items.
http://www.mediafire.com/download/zk...ansferCase.zip

SO you are saying my NP440 should do the trick .Is it the same as the A833 ? My truck is an 3/4 ton chassis and is rated at an 1 ton has an fleetside bed .I am running 16 inch 8 lug rims ( I got from an 1982 3/4 ton chevy) , converted them to the old 1961 snap ring fingers to hold the inny style hubcaps - so cool !
I remember my 66 Spicer rear had 411's in it originally and put in 354 ring gear. you said 411 is higher geared but my experiance is different here .