SS454 Facts:
No 4 speed's made
Not all SS454's had bucket seats, some were even bucket colum shift, bench colum shift.
Not all SS454's had Tach's
ALL and ONLY SS454's had the "boxed" rear control arms
ALL SS454's had the Load Leveler system. HOWEVER, some 402 Monte's and 350's ordered this system as a RPO, so there are some BB monte's that have the LL system and ARE NOT SS's (the 402's).
The SS's had special interior knobs in 71 (not sure about 70?)
There may be more, there is a great site
www.firstgenerationmontecarlo.com that has bunches if info.
Hope this helps, and be careful, they are now faking the SS454's pretty regularly.
Rich