Is this car a stick or auto? If it's an auto and you are planning on running a stock converter that will play into the decision too.
As far as keeping an engine with a big cam happy at idle in gear or not is all about the combination of timing, carb tune and the correct converter.
Cams need to be matched to the other components, heads, compression, CI, converter, rear gear, weight and intended use. That's why I recommended calling Dave, he has years and years of experience building engines and selling cams. It never hurts to ask.
