Help with LS swap radiator hose

[binford]

I found this thread and I have the Cold-Case LS swap radiator.
GMT558ALS which has a 1.5" in and out.
To get the Gates hoses to fit I bought an adapter.
ICT Billet 1-1/4" to 1-1/2" Inch Hose Barb Splice Coupler

Not sure why Cold-Case puts an 1.5 inch upper, when the LS engine is 1.25, so now I'm adding a reducer aka adapter, to the hose.
I down loaded the Gates catalog and Gates Radiator Hose - 20801 might be an alterative, but I have not held that hose in my hands. But it is 1.5 to 1.25

I have the two gates hoses mention above.