Both are black wrinkle in 1971. Orange didn't start until 72 (except for special hoods and B-bodies)
Dual snorkel for big blocks, unsilenced for small (same as 1970 SB air cleaner).
The 1971 big block assembly has a tube protruding from the driver side snorkel for the (passenger-side) breather hose.
Check out the pics here, they're really helpful :
http://www.nicksgarage.com/aircleaner.htm I used to have a lot of reference pics about air cleaners, but I can't find them again.