My 454 runs hot

I have just built a fresh 454 for my 69 Camaro and when it idles the temperature rises and rises. It has a brand new 4 core radiator and a six blade flex a lite fan. I am running a 160deg. thermostat and a Weiand aluminum water pump. As long as the car is moving the temp stays around 195 but if I idle at a light for any length of time the temp rises to around 220(I shut it of at this point) I am running an MSD trigger dist with no vacum advance with a 6A control box. I have heard that the wrong initial timing setting can cause an engine to heat up. I originally set it at 4deg. BTDC and the heating did not seem that bad but I am now running it at 8deg BTDC and the heating seems to be worse. This distributor is so tunable and I am not sure what I should be running it at. The engine has 10.2:1 compression with rec port heads and an original LS6 intake. It has a 750 holley carb with 76 primary jets and 78 secondary. Any help anyone can give me would be greatly appreciated.

What should my timing be set at?

I had a 327 with the same thing timing may help a little if is set wrong but seriously if you are cruisin for half an hour and your temp is ok but when you stop in idle or in traffic and you temp rises you my need to fit a well fitted shroud to radiator. After you have a shroud fitted and it only slightly helps you may try different water pump pulleys to change water flow pressure.

I tried running twin thermos on many different combo's on a 5 core radiator and it wasn't until i threw them in the bin and built a shroud thad i had success.Also another combo is to fit a twin themo's shroud unit out of late model fairlane,if you dont want to run a fan at all but an incorrect fit will result in loss of fan suction and result in OVERHEATING WITH NO VEHICLE MOTION