OK guys I am new here but drove my 76 Shyhawk with a 3 row V6 rad(only dif isthe straight neck instead of the curved neck) and a short water pump and a flex fan after I burnt up my electric from running it with no relay. And my car never over heated with a true 420 hp 327 (dyno numbers on a twin of it)on the street.
One most people think a Monza rad wont cool a 400 hp car but my buddy had a 355 street strip engine in his 71 Vega and never had over heating problems either.
Oh and I took a 350 hp 350 in an 86 Ranger and cooled it with a stock 2.0 4 cyl Ranger radiator so why wont your big dollar aluminums keep a car cool?
So here we go into heat management.
One very large and spectacular rule every one forgets is air flow through the core. Without this you can have a rad 3 time the normal size and never cool a car, Pure fact.
Another thing is if you run aluminum you MUST ,MUST ,MUST change your antifreeze religiously every year even if its not driven a lot. Some say you dont but a friend bought one of the custom ones when the hbody group bought(got same price I guess) and after 2 years its leaking from internal corrosion. This is because of 2 dissimilar metals and a 2 component liquid (um this is same chemical mix that makes a battery) and a corroded intake and Edelbroke water pump. After chemical testing his antifreeze (name brand and new)did not last 2 years and he even used distilled water too. Analisys lab stated that if he had changed it every spring he would have been in good shape but due to large amounts of aluminum and cast iron in fluid content it became a battery after inhibitor broke down (he even had extra water pump lube/inhibitor in it too) .
So in the ineterst of cooling, the coolant must move at a rgulated rate (ie thermostat) and it must stay in the core long enough to release the proper amount of heat (ie the actual condition of heat exchange) so as to manage the heat of an engine.
I have found on most street engines that the difference of stock over underdrive pulleys just doesnt free up much power for the most part (despite some peoples actaul quotes) over cooling problems.
So if you have a properly operating radiator, proper air flow and proper regualtion a car can and will function.
Now this said if your car creaps up to say 230 in traffic and stays there it will not hurt even over a long period of time, does this mean its over heating ,no it is a result of low air flow with proper heat exchange to existing air flow.
Most people keep adding stuff to the system without understanding how they work.
I used a 160 thermostat in summer and got crap mileage, went to a 180 and my mileage came back.
First I use a good condition rad (ie flows good) a good fan that moves plenty of air ( and not at 10000 rpm) till core cools and shuts off.
I have been using electric fans from factory cars for years, my favorite is the ones from older Grand Ams with 4 mounting feet and I always mount it on the inlet side of the rad (on upper rad hose side) and I use a thermostatic switch so it will come on till core cools and it drop engine temp ,then shuts off.
Another thing is I see that most people will run thier cars retarded in timing and this causes a lot of over heating too.
My 327 had the .125 pop ups in it and 71 cc heads and steel shim head gaskets and would never top 220.
OK and another great change and it doesnt have to be changed every year is Evans NPG+ coolant, it boils at 369 degrees with no preasure and has very low nucleate boiling threshold (ie it wont boil up next to hot spots so it absorbs heat) and it has no water so it doesnt cause corrosion as bad (if at all) in a multi metal system.
Most people limit their timing for some reason my 327 had 16 initial , HEI with stock weights, light springs and manifold vacuum advance and would give a total of about 55 to 58 degrees at cruise. Unless you have super new tech heads(ie Vortec, aftermarket heads) you can run this much and never have problems. The 2 best street heads available that i have best luck from without major mods are 487's and 441's (both used with bigger valves on Vettes) but thats just what I used till World started making good heads.
I have similar timing set up on my truck I drive right now and after the other engine(built in 97 for my 71 monte) and in my truck and driven from september 02 till last July 4th. now I have 355,SR Torquers with 202/160 and LT4 HOT roller and it works great and in my contiuously loaded 78C10 with no over drive it runs cool and still averages 14-15 mpg and I drive it 90 miles a day.
Here is the combo, your system must cycle the fan at low speed, if it has proper air flow/proper system design, it will not heat creep at cruise speed.
Seems to me if an Hbody system didnt work with AC condenser from factory, strapped with the lean emission carbs and all the garbage tacked on then your cleaned up properly jetted/timed engine should not have major problems.
Just my findings, leasons and observations from over 20 yrs of car building.