273 questions...a few of them

maybe its just the factory springs binding up...

My thinking also. Have your cam in the 273 commando in my Valiant with absolutely no issues, but my heads have the comp cams recommended springs. Also from my experience definitely adjust your intake/exhaust to the cam spec sheet numbers not factory numbers. These springs are cheap. You need them.
http://www.summitracing.com/parts/CCA-901-16/