Non-Mopar project I've been working on.

Yea that's the one,real popular back in the 70's they were safer than driving just the floor pan around I can't remember how many times I feel off the 5 gallon bucket. Life was good back then. I still remember my neighbor putting in a hemi think it was a 426 in a older bug he would drive that around and it would just spin the tires and he was afraid to give it to much gas. I lived in a crazy neighbor hood growing up.
I'm putting the heads back on my 340 and was wondering if I need to run the engine up to temp. and retorque the heads again