Campy axles are 26 tpi. Shimano, Suntour, Suzue, and pretty much the rest of the Japanese axles are 10 mm x 1 mm threaded on the rear, 9 mm x 1 mm on the front. The cheap Suzue's are an exception with a 3/8 or 5/16 inch diameter and 26 tpi gauge.
These are already 120 mm spacing, right, so what were you spacing them out to? There isn't a lot of extra axle length on Dura Ace axles, so if you are having problems you might have to go to a Bicycle Research replacement axle, which can come in a variety of different lengths and is quite high quality. The cost is about $12-15 depending on your shop. Some people riding bikes with very fat stay ends sometimes have troubles with insufficient axle length (Raleigh's come to mind).