I have a 355 that I had built and places in my 85 Olds Cutlass that I've adored ever since I bought it.  I had issues with the ignition to the point where the car wouldn't start, it was paid off so I parked it and bought a 91 Caprice Classic.  I traded that in for a 96 Impala SS.  And then I decided to strap the Cutlass' Olds 307 and put a 355 in it.  By this point the Cutlass had been sitting for 5 years.

This summer I put the 355 I have in it.  It has an Edelbrock 7102 Performer RPM cam and lifter set, 062 vortec heads that were port polished for 2.02 flow, Edelbrock 7516 Perfromer RPM Air-Gap intake, Edelbrock 1407 Performer Carburetor, Hedman Hedders, and Edelbrock 7800 timing chain and I installed a 180 thermostat.

I cannot get this car to run cool for anything.  I've let it run just to see how hot it would get but by the time it gets to 220, I get scared and shut it off.  Since the car had been sitting for so long I decided to get the radiator professionally cleaned.  So I'm good there.  I replaced the fan clutch and noticed more cooling but still not enough so I'm good there.  I replaced both upper and lower radiator hoses and it has a brand new water pump.  The fan shroud is also properly placed.  The water is flowing well and doesn't bubble at all.  When I drive the car on stretches at or around 60mph the temp stays steady, but if I hit a red light or traffic, it's going up.  The timing on the engine is within its recommended range, but I know for a fact I have a vacuum leak.  I've read a few of the posts pertaining to this issue and they've stated that a vacuum leak would contribute to heating issues, but would it make a difference of 20+ degrees?  I've spoken to a few radiator experts, they've offered to sell me new radiators but stated that a new one isn't going to solve my problem.  Today I even installed a flex-fan out of curiosity.  It still got up to 220.

I've tried to provide as much information as possible so that someone might lead me to a solution.  Any constructive replies are appreciated because this is driving me mad.

It sucks to have a car sound so good, but to only be able to drive it 3-5 miles at a time...

Also, if anyone has a set up similar to mine, could you post your average running temperature?  

More information that I remembered after posting this...

The block is from a 75 C10 truck...

I also have Keith Black Claimer Performance Series Pistons...

My engine is running kinda rich.  I'm seeing some carbon deposits on my plugs...  

No help from anyone?

At all?  

Hey man,
I understand your pain.    I have a 67 firebird with a 400 with the oppsite problem.  I can idle all day long (until i run out of gas) without overheating.  but when I drive it!  It overheating in 2 or 3mile AFTER I make a turn a corner. that I dont understand.  

I have placed the waterpump, radiator, spark plugs,upper and lower.  Have had three ppl do the timing.  and nothing.  so I dont know.  If you find something out Please let me.    

I surely will.  I have been scouring all kinds of hot rod message boards trying to find information or people with knowledge about these types of issues...

A lot of people have told me to remove my thermostat just to see if the temperature varies any...

Have you tried that?  I figure it's a cheap way of figuring out what might be my next step to getting this situation resolved...

Here is some information you might want to look over for ideas:

http://www.crankshaftcoalition.com/..._cooling_system

I also asked a knowledgeable member of another forum I frequent about your issue.  When he replies, I will post the answer for you in this thread...  

hey you said you had a vacuum leak i don't how big of a leak you have but a lean engine will run hot.  

I've resealed my intake to try to take of this problem.  I noticed that my intake gaskets were improperly installed.  As a result my carburetor is getting better vacuum than previously.  That should take care of the vacuum leak and if there is still one, I'd blame the distributor first...  

When you say the temp. stays steady at 60mph, what is temp? Sounds like your having a real problem getting air to the radiator. Any obstuctions in the path of the radiator? Did it run any different with the new water pump? Did the flex-fan make any change? Did the engine sit for a while before installing?  

At 60mph, the temperature stays around 200-210...

There aren't any obstructions in the path of the radiator. The fan blows directly into the radiator, surrounded by the fan shroud...

I didn't have any heating problems with the old water pump, but this water pump is running fine.  The water is flowing through the radiator with no problems, which is why this is frustrating to me...

The flex-fan didn't seem to affect my cooling.  It still got pretty hot even after I installed the flex-fan...

As soon as the engine was finish being built, it was dropped into the body.  It didn't even sit a week...  

hey i was under the assumption that if you used vortec heads that you had to use a reverse flow water pump. it's that way on 96 to 99 Chevy stock 350. this may or may not help you.  

Also , where is your temp sensor located? For the hell of it, try another sensor and gauge.  

is it a stock or a after market gauge and is the sensor in the intake or the head. it should be in the head.  

Really?!  A reverse flow water pump?  That could be my problem right there!  I need to look into this!

My temp sensor is located in my intake.  I've already received the new gauge since it has been determined that the one installed is bad.  I have another temp gauge on my radiator that I've been reading while trying to figure out this problem...

It is an aftermarket gauge.  In the head?  Forgive my ignorance, but how do you install the sensor in the head??  

Wait...

Is that reverse flow or reverse rotation on the water pump?  

Driver side head there is a plug between the #1-#3 spark plugs. That is the usual location for the sender, but it should only register a few deg. warmer in the intake. I think the serpentine belt system would be the reason the water pump would be reverse. Any SBC-BBC Chevy pulls coolant from the lower hose, forces it to the rear of the block, into the rear of the heads, back to the front, up the intake crossover and back to the radiator via the upper hose. Im still leaning towards that gauge being inaccurate or a faulty sender. You seem to have covered all the bases, but lose that flex-fan (horsepower-robbing, noisy junk). If you can see the coolant in the rad. running from the upper hose side, across to the other, its running the right direction.