My manual for a set of Torin 6 ton shows that as part # T46002C-3.
It states
for replacement parts Customer Service 1-800-222-5381
Not all components are available
When ordering the following will be required Model Number, Serial Number, & Description
Otherwise, I'd do as Corndoggeh suggested and machine it down from square stock (or even a big bolt), but to be honest I have had a pinless set of otherwise same (design, except 3 ton) stands in addition to pinned and don't hesitate for a moment to use them because the pawl has good engagement. If it didn't, I wouldn't use them even if they had pins.
Edit: Different manual for their 6 ton T46002A doesn't show part #s and shows a different phone #: 1-888-448-6746 M-F 8AM-5PM PST
or use this form:
http://www.torin-usa.com/customer-support/parts-inquiry.html