Duster 383 cooling issue

Do you have hood to radiator seal installed? I’m looking at the pulley kit and to me that water pump pulley looks massive diameter wise compared to crank pulley. I had looked at kits for my Demon and every one of the aluminum pulley kits underdrive the accessories. I ended up going with oem style v belt pulleys. Cooling at idle vs down the road it could be restricted airflow thru the radiator. If you have a thermal temp gun measure inlet to outlet temps on the radiator. Also check radiator for cool spots. It’s possible to have cold spots if when it was assembled some tubes got blocked with epoxy if that’s what they used. If it starts to warm up and you idle does the temp come down? As stated earlier where’s the timing set to (tune).