... tubes in a 2 row aluminum radiator in a 3500 lbs 11 sec street/strip car ? Concerned about driving in traffic on the street in the Southeast during the summer. Thanks. Dave

1.25" will provide more surface area for cooling than the 1", and a pretty significant amount at that.

My two 1" row aluminum radiator works great...never a cooling issue even in traffic during the summer.

There are several ways this can be answered, depending on who is doing the talking. Some make the claim that the only advocates of the 1.25" tubes are those companies with inventory that needs to be sold. If you contact the popular aluminum radiator sources you will get a variety of opinions.

Be aware that many aluminum "racing" radiators do not have a proper fin count per inch for low speed street use.

On my '65 I am using a two 1" tube aluminum radiator that I had previously used in my small block '67. With a parts store cheapie fan clutch and matching 6 blade fan and no shroud - it cools my 496 just fine at the drags and on the street/highway.

On a related note: many guys run their street cars too cool! Your street engine will run better, get better mileage, and the oil will last longer when the coolant temp is run nearer to 200 degrees.

Thomas

Mark, Bill, & Thomas, thanks for the input & feedback. Dave