shift shaft seal

got a 59 Studebaker gasser, 350/350 Chev. Trans is leaking from the shift shaft seal, problem is it is not the regular seal, it is larger. The trans is a metric 350. Anyone know where to get this seal. Parts stores don't list it.
Thanks in advance John

 

I would check at a local transmission shop. Talk to the techs in the shop. Most guys I know have a stash of leftover parts from jobs they do.

 

There is only one linkage seal size for a TH350. They are all the same for TH200,350,400,700R4,2004R. Some TH400s had a o-ring. Powerglide had a larger diameter seal. Are you sure your trans is a TH350?
Bill

 

Take your seal out and take it to a trans shop and they will match it up. I had the same problem with a 78 corvette with the same trans. And yes they are not all the same.