MY NP A-833 swap in a 1979 camaro:                           02/17/2010
-----------------------------------------------------------------------

Also known as a NP-440

The case has an NP casting in it with serial # C15453 and C152 on the 
other side. The nose cone extension has number C15402 with a date stamp 
8/14/78 engraved. Hurst shifter part # 410431B.

Case is cast iron, with aluminum output shaft. Some research reveals 
this was used in a Diesel truck application.  Based on the output shaft 
design, this transmission was use only in GM applications as it has a 
TH350 mount and rear spline. The GM option code was MY6. 

Most A-833 transmissions manufactured after 1974 were overdrive units:

3.09 1.67 1 .73

However, early A-833 transmissions were final drive:

2.47 1.77 1.34 1

I believe, all A-833 transmissions optioned for GM were overdrive units.


The dead center of the stock 4-speed shifter hole in the floorboard of a 
1970-81 Camaro happens to be 19.5. back and from where the transmission 
mounts to the bellhousing and is offset to the driver.s side by ¾. from 
the centerline of the tunnel. 

The NP A-833 mounts the shifter at roughly 18", and dead center. 

SUM-70000 shifter kit will work on the A833 trans.. For a camaro application,
you will need to lengthen the shifter rods by 3" on the 1-2 rod, and 1" on the
reverse rod. The 3-4 rod should fit as is. You will need to bend the 3-4 rod
slightly upward to clear the reverse lever on the trans, and clear the speedo
cable. As-is, with 1/2" spacers on the shifter block the shifter will be about
an inch to the left. You can cut and weld on a universal hurst mount to run
bolt on sticks to position the shifter properly for the camaro.


The A833 uses a 1.98" TH400 type mechanical speedo. Two units exist, one for a 
34-39 tooth driven gear, and one for a 40-45 tooth driven gear. Stock units 
typically have the 34-39 tooth unit installed. TH350 uses a 7/8 speedo sleeve,
and 700R4 uses a 2 1/8" speedo sleeve. They will not fit the 833 housing.