Actually I think we are all in agreement. I think Chevracer was only looking at what was available for a 2004 with a 5.3L in which the smaller radiator was the only option. Based on the info you gave I am 100% sure you have the smaller radiator. They didn't switch to using the wider radiator with the 5.3L until they switched to using e-fans from the factory.

 

you know ryan after thinking about the efans your right.... **** sorry about that.... yes i was just looking at what his would come with originally..

 

Yeah all in agree, that the Chevy measurements are from inside of core not the plastic covers. But a 34in was available in 2004 5.3 liter with a clutch fan. I have one!
has a clutch fan, not electric and measures 34 inside the core lips. 2004 GMC Yukon slt a lot of times gmc will release certain things a year sooner on some vehicles than move that platform into other vehicles the next year.