Personally I would lower it some. 2800 RPM is just what it says in the 71 SM.

A lot depends on how you drive it. I would lower the RPM and just warm the car up more before driving it. There are several settings for the choke system to get it to operate properly. Choke, choke pull-off, choke unloader settings, etc...

I always warm my vehicles up before driving them now, but back in the day, people would just hop in the car and drive it...I have my fast idle set about 1800 RPM on my cars.