OD or not OD, that is the question

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grjammer

grjammer

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I just picked up an A833, FBR looks to be 5.125..I saw both shifter arms the same direction and jumped at it, brought it home and oh no..76 manufacture date, and the big FBR, anyway to mod these to be standard 4 speed ratios? Ill be running a mild 360 with 323 gears. wonder how the OD would work. Probably I should trade it out? I dunno. how can I tell for sure..I cant remember how the gear levers or synchro gears move inside. been too long since ive worked on them.
 
OD 833 with 3.23 will work if you have short 14" and drive alot on the highway.
3.91 is a much better ratio for those trans.
It really depends on how you drive it.
 
Thanks for the inputs, not sure if I should just try it out for fun or not. any way to id the gear ratio's in the trans with the side cover off? and which way do the the synchro hubs move for gears, forward hub forward is 1st, back is second, back hub is forward 3rd and back 4th? assuming a standard 4 speed. guess I can count shaft rotations. I haven't popped the side cover yet.
 
I had a mild 360 with the 883 OD and 3.23:1 rear for a year or so. Effectively it gives you a three speed with an OD gear. Shift out of first at 6000 and it drops to 3300 in second. You can cruise down the highway at 70 turning 2200. It gives you big jumps from gear to gear. I switched the rear out to a 3.55:1 and it made the car a lot more fun to drive. It still was easy to miss a gear if you try to shift too quickly. I used the car that way for three more years before upgrading to a TKO 5 speed and 3.91 gears and a bigger Hugh's cam.
 
Have you confirmed that it's an od?
 
Easy to tell. The 4 speed 4th gear is the OD 3rd gear, IE looking at the side plate, rotate the front shift shaft CCW. That gear is the straight through for either box

So to tell quick if it's a 4 speed or OD, rotate the front shift shaft CW which will be 3rd (4 speed) or OD on the "OD."

Now just rotate the input shaft one turn and look at the output. If it rotates LESS than one turn, it's a 4 speed. MORE than one turn, it's an OD
 
If it's a 76 casting, the case WAS originally an OD. But it's so old parts may have been swapped around. That's why I asked. If it's the complete cast iron case OD, including tail shaft, that's a good transmission. It will live happily behind 400 or so HP. I have one myself.
 
awesone info, will try the shift testing this afternoon, I have a 741 open 355 and a 742 sg 323. Can I put the sg unit in the 741 case retaining the 355s? I think I can if I maintain correct carrier bearings but not sure
 
definitely an OD unit, should make a fun ride
 
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