There was a thread here for manuals, but some of the links have become broken
We "had no" free 71 manual, but you can download a 70, a 72, and a 71 "body only" manual. That is, no electrical, and other sections missing
70-71 Mopar Parts
[ame="http://www.abodyjoe.com/pictures/Misc.%20car%20info/1970-71MoparParts.pdf"]http://www.abodyjoe.com/pictures/Misc.%20car%20info/1970-71MoparParts.pdf[/ame]
72 Service Manual
[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/1972%20Plymouth%20Chassis%20Serv%20Man.pdf[/ame]
69 Dodge Serv. Manual
[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/69%20dodge%20service%20manual.pdf[/ame]
70 Dart Challenger manual
[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/70%20Dart%20Challenger%20Serv%20Man1.pdf[/ame]
71 Dodge Body Manual
[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/71DodgeBodyManual.pdf[/ame]
66 and 70 manuals. These use consecutive page numbering in your viewer instead of the Mopar "dash" system, so you'll have to play with the page numbers
http://www.mymopar.com/downloads/servicemanuals/1966_Plymouth_Service_Manual.zip
http://www.mymopar.com/downloads/servicemanuals/1970_Plymouth_Service_Manual.zip