My 77 L-82 is stock and runs hot but is that true temperture? Infrared the radiator and it showed 180 degrees! So if it is not boiling over check the common problems like no seals around the shroud or no shroud, lower spoiler for directing air. You can not modify what a engineer spent years developing and not have problems!

 

What temperature is "runs hot"?

 

You have more than 1 issue here.I'd also get rid of shroud and install dual fans. I dont think a single is gonna cut it.

 

you need a chin spoiler under the radiator that will help keep cool while on interstate.

 

That would be me. A mechanical fan is more or less aimed directly at the engine bay and over the top..
Electric fans, following the contour of the radiator are pointed downward, towards the crank. Almost at a 45 degree angle. So, very little external engine cooling is what I was referring to.

 

how about putting the bypass hose from the pump to intake back on

 

Your electric fan is only bringing in cooling air through the area it covers! You would be much better off to make an adapter plate (1/8" thick aluminum?) to cover the rear of the existing radiator shroud & with hole for the electric fan to mount over. That way, your fan is drawing air thru the entire radiator, instead of less than 1/2 or it.

 

Never had problems wtih rubber fuel line. Those spring clamps are good though

You need some belts, and ck your alignment. The fan belt is about to go and both look to be out of alignment. One thing at a time
If it were me put your lower shroud back on, any fan with or without a clutch and keep the electric that may be wired to come on at higher temps. i always drill a few 1/8" holes around the outer lip of the Tstat to help with air pockets.

As others said your initial and total timing can make you run warm also

 

THeres a lot of good and bad info coming at you pretty fast. Your fan doesnt matter when you are driving on the highway, its all air forced in by the air dam underneath the nose that you are missing. I was battling these issues as I upped my horsepower and being a 68, the air dam was tiny to almost non existent. I added about 3 inches to my dam and the temps dropped atleast 15 degrees. And there are about 6 seals around the radiator, the hood and I found one I'm missing under the front of the radiator support. These are needed so that all the air forced into the opening in front of the radiator goes through the radiator and not around it. A good way to test the air dam test is to raise your headlights, the added area of the light buckets that is blocking the air flow will lower your temps a few degrees. I had to take out he shields and raise my lights at a track event last summer. you can leave the fan shroud in place if you like it for looks but you can lose it if you dont car. With the fan attached directly to the radiator it will pull though fine but just in that 16" circle. If your car is fine in stop and go and while idling you'll be fine. If you put on a flat metal shroud you wont get the cooling at highway speeds unless you have the little trap doors to let the forced air through. You can see those at Dewiits. There was a member selling a nice one for a larger radiator than I have but it was for a 17" fan. It could be made to work though.

The TINY air dam about an 1.5"

4 inch rubber extension added ontop of the tiny one

 

You need the air deflector under the radiator, seals around the radiator to make certain all air goes through the radiator. Your electric fan is way too small and doesn't move enough air. Without proper shoroud for the electric fan it isn't doing much to cool the radiator. Your need at least 2600 cfm fan capacity to cool that engine. That fan is OK for a helper pusher fan, but not very helpful the way you have it installed and sized. If you install proper electric fans you will need them wired with relays as they draw a lot of amps.

 

I forget to add that you should put in the 160 thermostat to get the water flowing sooner and take 7T1vettes advice about checking the lower radiator hose. If itscollapsing you wont get flow. And make sure your pump is pushing water the right way. you can look in the cap and see if its flowing into the tank with the cap on it or not. Just pull the cap off before you get the car hot so you dont burn yorself

 

A 160 thermostat will do nothing to make the engine run cooler. Doing so will only lengthen the time it takes for the engine to reach its 'natural' operating temperature. The thermostat does NOT establish an operating temp....it merely establishes the MINIMUM operating temp of the engine. And at that temp the stat opens, ALLOWING coolant to pass through the radiator. At that point, the design of the cooling system and the amount of heat generated by the engine determine the system's operating temperature. And, if you don't believe that, REMOVE the stat and run the car. It will take longer to reach operating temperature, but it will operate at the same temp it did before....UNLESS the cooling system has an excess capacity for cooling (much more efficient radiator installed than the original unit).

 

Forget about thermostat, etc.
Until he installs the front air dam and replaces the sealing around the radiator there's no point in looking at anything else.
Then if it still overheats, and it will because the fan is too small, that will be the next fix.