Old Hot Rod Article about converting a std 4 speed to OD
Makes me wonder. If the input shaft is the same between a 3.09:1 first gear box and an OD box,
There are 4 fine-spline A833 ratios, and AFAIK there is only one gear that interchanges between any of them, namely the low gear in the 2.66 box and the low gear in IIRC the 2.47 low box.
ZERO of the other gears, AFAIcan remember, are interchangeable.
I have the tooth counts kicking around.
I'll see if I can find them.
Hang on.....
Nope, they're packed away.
BTW
there are TWO, A833 od ratios, namely
the common .73 od, which has a 20 tooth od gear, and another that
I found; the .71od, which has a flimsy 18 tooth od gear.
As far as I recall, NONE of the gears interchange.
That .71 is worth 60rpm at 65mph..... over the .73
I have been told that the .71 comes out of a chevy truck......... but mine came out of a friends F-body, and has a 1x23 spline input. but with the smaller 904-sized output shaft splines. The seller said it came out of a slantycar.
If anybody out there wants to build a 3-speed A833, I have several copies that in a former life were overdrives, but those tiny 18 toothers are MIA.... lol.
Ok found them!
here is a summary of the tooth counts, for fine-spline A833s;
25-29-34-35 ---- the 2.47-1.77-134-1.00 often called the "close-ratio" box
30-26-23-17
--------------
24-29-34-35 ---- the 2.66-1.91-1.39-1.00, standard from 69 down
31-27-23-17
--------------
22-27-32-35 ---- the 3.09-1.92-1.40-1.00 , often called the Commando
33-29-25-17
---------------
22-18-30-35 ---- the 3.09-1.67-1.00-.73od, the F-body box
33-37-27-17
---------------
24-20-30-35 ---- the 3.09-1.67-1.00-.714od, mine (79/80 Aspen slanty)
36-42-27-17