[Steve Jones]

Bill,
You have to be carefull there, I think the Ford FE applications that use a gooseneck at the manifold (Mustang 428CJ for one) do use the small thermostat. The FE applications that use the expansion tank bolted to the manifold use the 2.50 inch thermostat.

I just received the Chrysler thermostats from Jegs and Scott is right, they are the right size for the expansion tank and I will be installing one this weekend. There is a significant difference in the size of the passage diameter. I just hope they're as accurate as they claim. They do not, however, come with a gasket. The Fel-Pro number for the right gasket is 35063 (or NEA 677). Thanks Scott!

Steve