Ok, new radiator cap is on. I will run it a bit and see if it helps.
Also, I bought some of the constant tension hose clamps. I ordered these 1-15/32" - 1-3/4" ones, but they only will fit on the upper radiator hose radiator side. What is the recommended sizes for the other clamps? I.e. upper radiator hose engine side, and both ends of the lower radiator hose? I know I could figure it out, but I am also pretty sure one of you guys (e.g. @Chris) knows off the top of their head.
I don't actually know off the top of my head unfortunately, but if you find out, I'd like to know. If you have the other hoses off, you could measure the diameter of them to know for sure. That's what I'd do actually.
It might be nice to compile a list of hose clamp sizes if possible. I'm sure a lot of people would find that helpful.