I've searched through old manuals and online and have found precious little information on this topic. I'm looking for info on the 3 speed manual transmission with overdrive that would have been optional on mid to late 60's Chevy's. I believe it was only offered behing the 283 (on the fullsize models anyway). I think at least 65/66/67 were the same. Not sure beyond that. I searched this forum, and aside from the thread on the '57 overdrive transmission there wasn't much else. Online I've found reference to the T85 and T86 but neither of those look like they are the correct trans. Does anyone have any info on this trans? Who made it, RPO code, etc..

Don't know any codes. but they came in some 55 56 57 chevy's, I had a 56 with one in it, brother got one out of a 55 for his 57, He's still got it, I think. They had a cable that engaged it into overdrive and it also had a kickdown switch to take it out of OD at WOT. Now thats to the best of my recollection, but I WAS wrong once back in 19 uhhhhh something.

If it's '66 or newer it's probably a Saginaw.

Thanks for the replies. I did manage to find a little bit more information now. You are the second source that has said it was a Saginaw so I'll take that as truth. I wish I could find some more technical information on this. All I seem to find anywhere are vague references to it. More searching....

I found this article online while searching. This appears to be the correct transmission. Seems like I've found more of the 5?-64 transmissions around. Well in case anyone else is interested
Saginaw Overdrive Trans Rebuild