Cooling fan problem

I recently rebuilt a 350 for my old 1991 RS, and it had a 2.8 V6 before the 350. The fan on the car right now is a 14 inch fan and doesnt seem to cool enough. When I drive constantly fast, like on a highway it doesnt get hot, but just cruising around down it gets super hot. Would a larger fan pull more air off the radiator???I've changed thermostats, new water pump, new rebuilt engine, i'm just running out of ideas. Any help?

Im shure you didn't have the 2.8 because the last year it was it the camaro was 89...lucky me :crying: I think the V6 would have been a 3.1, but I dont know for shure...
Was the fan switched when the engine was switched? I know the V8s needed more air pulled through the radiator...I think they have a dual fan setup.
If the fan wasnt switched at the time of swap, I would recommend going to a salvage yard and getting the dual fan setup out of a v8 camaro...you might also need a bigger radiator...
Dont drive your car around until you get this fixed, you dont want to overheat that new engine...would be a shame...

Did you replace or reprogram the ECM?

Most importantly is the air dam in place in one piece?