I found a Stock Eliminator car in the Blueprint/Car Classifications but..

[art leong]

Some times there are typos in NHRA's book. Check the real stock parts and see if it is.
If no piston manufacturer has submitted a piston, there will be no replacement pistons. You have to use the ones that are made by the manufacturer. As far a runner volumes goes they have never poured that particular combo so there aren't any numbers yet.