Can someone help me find an upper radiator hose?

[derotoreut]

I'm doing my first LS swap into my '70 K10 and for the life of me can I find an upper radiator hose that will work. I've seen what a couple of guys have done, but it doesn't seem to fit my application. I even took a piece of flexible air intake preheater hose, molded it to shape and took it into NAPA to try to match something up. No luck.

My swap is a Gen III 5.3L LM7. I'm using a radiator made by Northern that has upper and lower radiator hoses on passenger side. The lower radiator hose connection is 1-3/4". I was able to use Gates 20687 for the lower. The upper hose connection is my problem, it's 1-1/2". I've seen where guys have used the Gates 21439 for the upper, but this hose is 1-1/4" and just does not line up. Does anyone have any ideas on something that might be close?

For the upper I'd be going from 1-1/2" at radiator to 1-1/4" at engine. I could always use a 1-1/2" hose with reducer if need be. I had someone give me some numbers off an upper hose that they used, but I can't seem to get these numbers back to a useful part number. The numbers are 80GN25 and 1451.

Hose has 80GN25 Made In USA


Hose also has 1451 number on it


My 5.3L LM7 with Northern radiator