I would suspect it's the same for E-body and I've been looking for one for a while, too. (Like you, I figured there'd be a ton of them in folk's garages, saved from dual conversions. Apparently, not everyone is at the same level of hoarding as I am.)

Anyway, I bought a new Y-pipe for Ramcharger (mid-80's?) thinking it would be similar. NOPE, not even close or usable. $80 lesson learned.