Gentlemen, I am putting an aluminium rad in my 383 car. It was formerly a 307. So, I thought it a good idea to transplant the two row core rad from it into my 250 cid six banger ( which appears to have one skinny row in the rad ), on the assumption that "If some is good more is better." My pal, who is helping me get deeper into understanding all the mechanicals, electric, vacuum, tuning etc., tells me "Absolutely no way". The engnineers have made all the components ( fan, rad, thermostat etc. ) to perfectly match and if I mess around putting in a two row core, I will be commiting a sin. I don't see what's the big deal. Any reason I can't upgrade to a two row core in the I 6? Thanks for any consideration, R. B.

I can't see how it would hurt, seeing as the thermostat controls the flow of coolant to the block.
The bigger the better where I come from, but in Canada ? Maybe it's a no no ??? :confused:

The more efficient the rad the better off you are ... yes in a good cooling system the t/stat will (control the over all temp) and modulat to keep things on track ... in a bad cooling system the t/stat will only control opening temp .. and you watch the temp gage to to 210 degrees .

we have done some 700 hp cars with our rad .. and the pop in a 160 t/stat and the car never gets hot meaning the stat is modulating just to keep the block at 160 ...180 would be the min stat to burn off moisture in the pan .

Don