I like the scoops, and im not trying to put down anybodys work.. and ill even add in that ive never even been able to drive my C3 yet

But I'll still say I think somethings wrong with your cooling systems besides airflow if you cant keep it at whatever your theromstat is at during a 50 mile cruise! (which could simply be a fautly water temp sender or guage for that matter)
My firebird does not even have a grill, it relies entirely on the air dam underneath to get any air directed to it (which Ill even go so far as to say is probably less then what you get with the corvette, I think the rad itself is smaller, and I know my car sits lower) and it will run 180 all day long on the highway.... granted thats with overdrive, I think someone else mentioned earlier that his overdrive tranny dropped temps signifigantly..
And with the electric fan I can keep the car at 180 just sitting in traffic..

My intrepid got its entire air dam ripped off a few years back and I never even bothered to replace it because it never had a cooling problem without it..

So I dont know maybe its the 1:1 with 3.73's in the back at 70mph.. *shrugs* however I know plenty of those guys with no cooling complaints either

 

I dont understand the cooling problems

I have owned two Corvettes... both 73's
The first one was in the early 80's and it was far from stock.
I was told it was an LT-1 but I have no idea what it was as I diddnt have the resources I do these days...all I know is that it would have eaten my current L-48 alive in 2nd gear
Both cars - A/C equipped and I never had a problem with overheating..
If I put in a 180* thermostat it would run very close to 180*
I dont understand the cooling problems....
What am I doing wrong?

 

Part of my problem is I'm missing the side seals around the radiator, and I beleve it is the origional radiator from the factory, that probably needs a good cleaning to remove the noticeable scale buid up.
Also it is not the origional engine. So I can not be sure if the fan and clutch are correct.

 

In my case,I have the original 78 L-82 engine, 4 row C/B, A/C, stock 7 blade fan, all new seals...but....the new clutch fan calibration is set at higher temps than my old GM clutch fan....this has caused a shift in my operating temps.
**Original clutch fan fully engaged at 190 F**
**New clutch fan fully engages at 220 F**
That is a big difference..
Rich

 

When I start my 73' and start to drive I can ALWAYS hear the fan engaged
After a few seconds it dis-engages...I dont know if anybody else has the same experience but my 99 Explorer V8 does the exact same thing
I would guess its a test functon of some sort

Next time you drive your car with a clutch fan listen for it

 

Good tip Bob...and I hear it ...but I'm either adjusting spring to re-calibrate clutch or finding one calibrated same as original...

Another point is,the replacement fan clutches today are not same quality as original fan clutches of the 70's..and Hayden aka Four seasons aka Airtech all samo samo..

 

I like the long one better...the air dam was just an afterthought by GM to fix overheating problems with the more powerful motors. The L-82 wasn't the cooling problem...it was the Big Block engines that carried over from the Sting Rays.

The "gills" were added in the design just to improve air flow in the engine compartment...the original proto type had clean fenders. In fact, the original Maco Shark proto type had side exhaust coming out where we now have the side air vents. A front spoiler was actually reduced in size so that more air could be scavenged by the air dam...which was also new to Corvettes as the Sting Rays had neither open air vents (they were just for show) or air dams.