The autoparts store has a slinky style lower radiator hose (mine does). I made my own from a stock house and another hose I picked out because I like the shape, plus a stainless L. My car has an aftermarket air conditioner that prevents the stock hose from working. Yours?
Max, my 52 Buick was in an accident last fall. I had a new radiator built, I was able to salvage the lower neck on the old radiator and use it on the new radiator but outlet location is not the same as the old radiator. A flex hose would work as there are several angles to contend with between water pump and radiator. My Buick motor is a 425. Larry, my water pump inlet is 1 ⅝ inch as is my outlet on my radiator.
Since the lower hose is on the suction side of the system just be sure that the hose you get has a spring in it so it does not collapse on you . Upper hoses you may be looking at will not have this.
Well, this is too expensive, and it is 4' long, https://www.amazon.com/Dayco-75163GL-Automotive-Accessories/dp/B002M1CBLQ This one is molded, and 1.750 on one end, https://www.summitracing.com/parts/...iR2ACaqKZgVTTCFGTFx6KSKyohuJQEXEaArjGEALw_wcB 1 3/4" would probably work fine with a clamp, and be easier to find. https://www.gates.com/us/en/fluid-power/engine-hose/coolant-hose.p.4284-000000-000000.html https://www.performancebodies.com/products/gates-flexible-radiator-hoses
i have used a 1 3/4 hose is place of a 1 5/8 but first i cut part of a 1 5/8 hose and slid it over the neck. they even sell adapters for doing that.
Thank you for all the ideas. Your search for 1 ⅝ inch flex hose was as futile as mine. I found a 1 ⅝ inch combo exhaust pipe mandrel bend at Speedway Motors. I will cut it up and weld it back together to get the angles I need. I have some short pieces of 1 ⅝ inch hose that survived the wreck so with a little work I will have a lower radiator hose that will not collapse.