Stupid Radiator hose fit question

[oteixeira]

OK, so I swapped in a 5.3 and now I can't figure out the radiator hose to buy on the low end. I hand measured, and the inside diameter of the 5.3 hose seems to be 1.5 inches, the diameter of the radiator is 1.25 inches. I thought I was set, found a bunch of hoses, then I went to double check, and rock auto and other retailers online say my hose (for the radiator of a 1970 C-20) should be 1 3/4, and that would be way to big. Are my measurements not where they should be taken? Should I have done outside diameter ? I don't want to buy a hose just to chuck it away.

Thanks in advance,

Orlando

[69GMCLonghorn]

In a situation like that, if it's possible, I like to bring the vehicle (or pieces thereof) to the parts store so they can see it firsthand. In liew of that, shoot a few cell phone pics and show them what you are referring to.

[cdowns]

you should be taking outside diameter of water pump outlet and radiator outlet so they can give you proper hose insde diameter to fit over the outlets

[smoky02]

There are radiator hoses that are bigger on one than the other.

[oteixeira]

I am sorry, I should have been more clear. What I am calling inside diameter is actually what I measured from the metal edge to metal edge of the pipe coming out of the bottom of the radiator, so I would guess that is the outside diameter of that pipe. As for the other end, I had the hose, so I just measured that way (turns out it is actually 1-17/32) and that hose is too big for the radiator end, so no way it will work with a 1-3/4, right? Now I am curious what kind of radiator was in the truck, it was in good shape when I got the truck, so I kept it, and it had no issues cooling the 350/th-350 that was in the truck.

Orlando