Sighting on the Reading Line in Allentown

Earlier this evening, on Wednesday, 9-Jun, 2004, I saw a freight train on the reading line headed west. I saw it right behind the Turkey Hill on Lehigh Street in Allentown. Right behind the engine were some passenger cars. They were stainless steel, but they reminded me more of MNRR and LIRR's MU's because they had 2 sets of center doors but no end doors. Headed west from Allentown, I doubt they were MNRR or LIRR's. Does anyone have an idea as to whos / what they were?

Were they on flatcars or anything??

I think they were running on their own wheels

Hmm..maybe some NS Test cars or some special thing?? who knows...