[BigMike]

Sorry, it's a long post. But I figured I'd give you all the info I thought you may need to help...

I have had a heck of a time trying to figure out the overheating issues in my truck. I've replaced & upgraded several parts trying to figure it out but now I need professional help (with my truck too).

I bought the truck (basket case) back in '05 and finally got it on the road in '12. From that point till now it has over heated. Engine is a 86+ HO GM crate motor. It runs great at lower temps but once it starts going above 210+ it starts to feel like it's going to die and I need to have my foot feathering the throttle at idle. Once it dies it will not start again for another 15 minutes, at which time it will fire up and run until it gets around 210+ again then it acts up again. No steam or white smoke so it's not a head gasket.


Engine is a 86+ HO GM crate motor
TH350 (soon to be stage 2 200r4)
3:73 posi rear
Mallory Unilite electronic dist
Edelbrock 1406 Electric choke
Sanderson shorty headers
Edelbrock high volume water pump
Edelbrock 2101 Performer manifold
Aluminum 2 core (1" tubes) radiator
Dual 12" electric fans w/Aluminum shroud
180 Thermostat. Dakota Digital sensor in the front of the manifold.
Dakota Digital VHX gauges and a DD fan controller
Timing 11 degrees, 38 degrees total


I replaced the oem style 4 core copper radiator with an aluminum 2 1" tube radiator - still overheats. All air removed from radiator and mixed half distilled water & half antifreeze. Overflow attached and filled.

Changed the factory clutch fan with dual 12" with aluminum shroud - still overheats

Added a polycarbonate 1" spacer under the carb because it seems I was getting vapor lock, not as bad but still does when it gets hot.

Could it be the carb? I am at a loss because it all of the cars & trucks I've ever owned I never had issues keeping them running cool with just the factory components. In the cooler (low 70's) times of year it runs great and really has no issues. But once the temps get around 80+ I always have issues...which is what the temps are most of the time in Southern California. Anyone have any ideas that I may not have tried? I've researched for hours and hours on the subject and everything I have found was either already done, or I tried it and it didn't work. The other option is taking to someone that knows all about cooling and tuning and have them see if they can find the problem.

Thanks...