Go to the Edelbrock's web site, look under the tech installation pages for their RPM heads for Mopars and the last thing they say is allow a cool down of 2 to 3 hours after initial start up, and RETORQUE the head bolts.
They make em they should know.
It was alot of work on my engine to do, but I found them loose.
After just spending over $1000 bucks to get the heads repaired because they were not retorqued by the previous owner, I wasnt going to take a chance.
Go the extra mile to retorqe, its just time, not $$$$$$$$$$$$!