Brandon, the OP asked his question year and a half ago. i'd think he probably already got his answer .
but as far as i read they are not "grain hoppers" per se but rather 3 or 4 bay covered hoppers. when new they will cary grain and bean and such. as they age and no longer meet sanitary requirements they will get degraded to non foods loads such as plastic pellets (although i hear dedicated cars are made for specifically that load), and as EOL date nears even non full loads of sand and cement. or so i read
I bought 36 and they fit my Athearn cabooses and one Athearn tank car just fine but were tight on the Model-Power cylindrical hoppers. But the trucks could have been just too old to bend to fit them in...I don't know.
Thats very true, so thats why i appreciate all your help. I would be lost without the help of a veteran like you on this site. So once again i look forward to hearing more from you, and im def gonna keep in mind to check the dates lol.