My 1950 4-speed Hydramatic trans is not shifting right. I will be in third or fourth gear by the time I cross an intersection (from a complete stop). I would like to change the shift points and wonder if I can do that myself from outside the transmission as I have no desire or training to open one up.
Also, I can not get the trans to downshift when I put the pedal down to pass someone. Is this related to the shift point issue? Can this one also be a DIY fix?

 

Yes it can be a DIY fix .
The problems you describe are probably due to a mis-adjustment of the throttle to trans linkage .
If you don't have one , get a 1950 Oldsmobile Shop Manual . https://www.ebay.com/sch/i.html?_fro...963+oldsmobile
There will be a description of the proper way to adjust the linkage .