Does anybody know which hose Im supposed to cut in the t valve to flush out the old dexcool? There is a large hose (feeding?) the heater core and a smaller one returning to the engine. I would have thought to backflush I should install the t in the small return line? Anybody know for sure?

You could use either heater hose. However to help bleed air in the future, I'd suggest the higher of the two if one is higher than the other.

Wouldnt it be more productive for flushing to reverse the flow in the heater core and the engine. As opposed to the way it normally flows when being pumped by the water pump?

yes, however, when installing a "T" your not actually forcing water in one certain direction....

i think... its early.... and its monday

No, by adding a T, you are forcing water in both directions aka T

If you want to do it my way, skip the T, unhook the heater hoses and flush the block through each hose inlet back to the radiator, then from the radiator back, and through the waterneck, and flush the heater core seperately...both directions on easy and every way you can.

That'* a full flushing.

IIRC, if you purchase the Prestone Flush Kit, the instructions say to put it in the inlet heater hose, without an explanation as to why.

Dick...got the inlet identified? I forget if it'* the top or bottom on your year.

Thanks for the gentle nudge, Bill. That would have been useful information to provide. The top hose is the inlet.

Would the Larger diameter hose always be the inlet or the the one feeding the heater core?

Like "never say never", also "never say always". For instance, some vehicles have the same size in and out. In this particular case, the coolant comes out of the top of the tensioner from the outlet closest to the alternator, runs through the heater hose (which in this case is the larger of the two hoses), through the heater core, back out through the other heater hose and back to the tensioner on the inlet that is closest to the firewall.