If your mopar is you daily driver!

Jamesm proper engine temps is a fatory set item that a few degrees ethier way doesn't have a big effect. While longevity could be a fdactor, I have not personaly totaled over 100,000 miles on any of my rides. Though my wifes Ford has personaly seen 130,000 by her foot alone, it has not been modified except the Accel coil pac and K&N air filter. Synth oil is also used. These 3 items in concert have added about 2-2-1/2 mpg's.

Back to topic at hand, sorry.

To high a temp can cause pinging, un burt fuel due to detination just as a cold (Think winter cold) running car doesn't burn up all the fuel. It's basicly a step to far or much of you alter the running temp that much on a stock engine.

You would want enuff heat in the carb and intake track to help atomize the fuel and run well. You could jet the carn to run great on a stone cold engine. But what happens when it warms up? It runs lean. If to lean, your not only down on power, but you could end up miss fireing. Gas wasted.

So a heat crossover is good for quick warming of the engine to achieve operating temps. You don't need it, but it sure helps when it gets chilly out. It'll help with fuel mileage because it warms the car up quickly and allows the fuel to be burnt better.