My Griffin radiator is a 2 row 1" tubes. I have the 35 gallon per hour electric pump. A 165 degree thermostat. That may be one of my problems, the thermostat is too cool. My bad i wasn't thinking about that when i put it in. I had a brain fart, lol. I would like too change the water pump to a mechanical, but that would mean i need to replace all my billet aluminum brackets as well. Another huge cost, but not as huge as a motor rebuild. I have nearly $15,000 in this motor so i need too be more careful with simple little mistakes as a thermostat. I have 2 fans on it as well, 1 pusher, and 1 puller, one at each end, in the front, and back of the radiator. Guess I need too make a couple changes. Thanks guys for your help. Love this site. So many helpful people.