Lower Raditor Hose/High RPM Cooling

Forgive me if this has been covered lately but I couldn't find it in a search. I have no problem day to day with cooling, but today for the second time I hit 230 F on a stretch of interstate with a 70mph speed limit. Had a stiff headwind and a trailer. Temp was 190 until I got annoyed at the OD to 3rd downshift on every moderate grade and pulled her into 3rd. This worked great but the temp needle started going up and stayed up until I backed off and shifted to OD. Just doesn't make sense unless high rpm makes the water pump cavitate. After a period of idling at a standstill, temp goes back to 190. No leaks.
Questions:
1. Is the lower radiator hose the suction side of pump?
2. Isn't the lower rad. hose supposed to have a spring inside it to hold it open? Mine doesn't.
3. Anybody had a similar problem?

I can pull the trailer all day and just tolerate the shifting or let the speed drop a little on hills and avoid the downshift and the temp gage stays below 200. I have a trans oil cooler and new water pump. Low speed idling and stop and go traffic do not cause this problem. Just when I hold it in a lower gear and wind it up a little it starts getting hot.
Thanks for any advice.
If I get an OEM hose will I get the spring with it?

On the wifes 87 after replaceing a water pump, I had the same problem. The spring was a little short and I´d let it slip to one end. High RPM and the suction would partially close the hose.
I´ve used a universal type bottom hose with the spring built in, with some serious tie down with large cable ties.
The moulded hose is much easier though. Springs are probably available, they do rust and need replaceing. I pulled a selection at the junk yard, for projects.

Yes the lower hose is the suction side, and yes it should have a spring in it.

The same thing happened to a friend of mine. His XJ was fine around town, but on a trip after 20 to 30 minutes it would overheat. If he stopped for 10 or 15 minutes, it would cool down and he'd start on again, only to have the same thing happen. We finally traced it to a short (not totally absent) spring, same as 8Mud. My friend stopped by a raditor shop, where they let him scrounge through the trash and he salvaged a couple of lengths of spring. Stuck one into the hose and that was the end of the problem.

When I replaced my lower radiator hose I went to every parts place in town trying to find a hose with a spring in it and none had one. I sucked it up and went to the dealer and purchased it there and it had the spring in it. :rof:

Thanks everybody! I love this site.

I forget who posted it last week or so but that fancy XJ with all the underhood plumbing looked like it had some kind of solid steel hose, whats up with that and what kind is it. I'm planning on a complete cooling system overhaul this spring and if that kind of solid hose is around I'd like to take a look at it, see if it has to be specially bent or what.
A few years ago in NJ there was a speed shop chain called 'Van Iderstein speed shop', they carried Russell hoses and fittings and sold the stuff by the foot, while it was about twice the cost of normal hose it sure went in nice on my 69 Willys custom wagon with it's 360 buick engine but I never see that stuff around anymore.
I had started my list and was about to hit the dodge dealer who order my jeep parts [and gives me a nice discount] but would like a better alternative to plain old hoses... Any suggestions for a wizzbang option ???