I have a Camaro SS396/325hp/400auto(#'s match).........The original rad rotted out and all of the hoses and belts had to be replaced... So I went out and got a Griffin Radiator, Big bucks.....The Rads core is 23"X18" and bolts in perfect... Has trans cooler built in...has a 180 stat....Has a 19" wide blade corvette flex fan..Factory fan shrould....and I went out to American Motor Sports and picked up a new Aluminum water pump...I still can not drive this car around the neighbor hood without over heating at a stop light (210 plus)
HELP...Please...

I Had A 69 375 X66 Car With 4.56 And Auto Also Ran Hot,turned Out To Be The Clutch Fan Was Not Engaging

I have a Camaro SS396/325hp/400auto(#'s match).........The original rad rotted out and all of the hoses and belts had to be replaced... So I went out and got a Griffin Radiator, Big bucks.....The Rads core is 23"X18" and bolts in perfect... Has trans cooler built in...has a 180 stat....Has a 19" wide blade corvette flex fan..Factory fan shrould....and I went out to American Motor Sports and picked up a new Aluminum water pump...I still can not drive this car around the neighbor hood without over heating at a stop light (210 plus)
HELP...Please...

Corvettes never used a flex fan - they used clutches and rigid fans. Does your distributor have vacuum advance? If so, what's it connected to - ported or manifold vacuum? 99% of idle heating problems are caused by inadequate airflow and/or retarded ignition timing (no vacuum advance at idle).
:beers:

JohnZ may be on to something,..retarded timing at cruise and idle keeps heat in the engine.

But, something is definitely wrong.

I'm running a factory style 4-core radiator with a 496 (10.5-1 compression) with 3.90 gears and she never sees the other side of 185. I do use an Edelbrock alum hi-flow pump, hi-flow stat, and alum heads,..and it is a stick car with no a/c. But still, your 396 shouldn't have any cooling probs.

Maybe blockage,..have you ever used any of those 'stop-leak' products?

Secondly,..it's been proven repeatedly that flex fans don't perform as well as a typical factory seven blade fan with a fan clutch.

Ground Up has a great kit,..has the Eaton clutch, 7-blade fan, and hardware...$139 for the kit...a great buy...part number FANKIT-7BL for a 69. It would be a different kit for a 67-68 (short water pump).

Are you using the little bypass hose that goes from the pump to the intake?...it prevents the pump from dry-spinning.

Lastly,..are you using factory exhaust with the crossover stuff? If so, could the heat riser valve be stuck closed?

Thinking out loud...Good luck!

My first instinct is blockage in the motor. Has it ever been rebuilt.?? if the radiator was clogged and rotted, you may have plenty of gunk in the motor too, in the water jackets which will impede flow. Is the coolant green or is it a chocolatly brown.?

Everyones posted some good thoughts, but did you ever consider after changing everything that maybe it has a bad vapor lock? Also, how fresh is the motor, I don't want to scare you, but it could be possible that the one of the heads has a small crack or pinhole thats leaning out one of the cylinders and causing the motor to overheat, I know this happen to my cousin's 427, after troubleshooting everything else, same senario, new radiator, water pump, fan, etc, finally pulled the heads and pressure tested them at the shop to find a pin hole in one of the heads.

By "vapor lock",..I assume you mean the water pump is dry-spinning. Could be it,..the little hose between the pump and the intake prevents this.

Yea, thats what I was referring to, didn't realize you mentioned that already.