Rear Suspension ??'s 66 LWB

[66herbie]

Hey guys, have had my 66 since 05, when i was 15. did a "restoration" if you wanna call it that. quick fixes on some things, paint, wheels. called it good. Anyways, can't seem to find any other info on this as to why, but the rear suspension on my truck has the leaf spring setup off a 4x4, however this is a 2wd truck. Has been in the family since around 1970 and has not been changed over to that by anyone that we know of. my question is did some of these trucks have this as an option on 2wd instead of the trailing arms and coils? It is an original custom, if that makes a differance. Thanks in advance!