Gerry
Lionel E units are usually coupled fairly.close coupled unlike how F units had up to the latest releases much larger gaps, Check the Lionel parts website for your E6 note the length of the rear non operating coupler. Then check their E7# and E8s if they are shorter order two. They should fit but note the mounting on your and make sure they match on the E7, E8 ones. Good luck.
JohnB