I have a '68 OW trans (original tag and case VIN matched to car), but was curious if anybody knows how to identify the valve body to tell if it is still the original... I took some pictures of the stamps I could find on the valve body when I opened it up and attached them below. It has "30" stamped in two places on the valve body, and another yellow number that isn't discernible anymore.

I looked in the '68 Chassis Manual and it didn't even identify an OW trans for '68 (W-30 and H/O must have been a late addition?). Based on one or two mismatched bolts on the trans pan, it's been opened before (unless those 2 mismatched bolts were intended for the shifter bracket, which is possible). It's been sitting a while and didn't look so healthy inside, so it's on its way to the rebuilder. Figured I would document this first in case the stamps go away.

I saw some pics from jensenracing on a '70 (https://classicoldsmobile.com/forums...-ow-trans.html), but nothing on a '68... Thanks!

 

I know it doesn't help but OW tranny's were definitely referenced in the Assembly Manual (added 9/29/67). I've got the 68 Service Manual Supplemental at home. If you haven't found anything by tonight I'll look through it and see if the chart on page 7-84 has been updated. This is the speedo drive gear chart from the Assembly Manual:

 

parts book shows a valve body # of 8626212 for 68 ow.... if you take it to a shop make sure your ow tag doesn't go missing

 

Thanks guys! Saw that in the assembly manual, didn't see anything else in particular, let me know if you find anything in the supplement. Interesting on the parts book.

The trans is going to a one man show who mainly does GM transmissions for several friends who race. He's trustworthy, so I'm not concerned there.