ST10 are not plentiful in my area or all the hot rodders just throw them in the corner because they don't think they are worth anything. The last ST10 I bought cost me $500 w/ an 11 inch clutch and bellhousing. It came from a '79 Corvette. The below is a quote from Paul Blaccard in response to a question I asked on the bullentin board at the this site
www.gearzone.net
By Paul Blaccard (Admin) on Tuesday, October 27, 1998 - 07:46 am:
To Mike Crosby: You cannot tell from the outside of your ST10 if your gears are 9310 nickel. Nickel alloy gears have drill marks that Identify them as such. A drill mark is a 11/32 OD hole that looks like someone started to drill a hole but stopped. Here goes: The input will have a drill mark where the ID of the front bearing presses on it right below the snap ring groove. The cluster will have a drill mark on the front face above the thrust washer surface. 1st has a drill mark on the back side. 2nd and 3rd have drill marks between the ID bore and the synchro cone surface on the front side.
Just a little more info for all Hope this helps.
Mike
[This message has been edited by Mike Crosby (edited 03-03-99).]