Is it normal for a pair of Stellings to be so hot I burned myself?
Water pressure is 22-25psi.
This is even after a run, not just idling.

I have burnt myself on my CMI's closer to the head, but tops are always cool to warm.

What was water pressure before? High water pressure is sometimes a sign of low flow after the engine

hmm I`m wondering if there are not enough water slits in the tails causing high pressure.. It was 34psi and going up before I put the blow offs on

I have a hot spot on the port side dry tails I just made and I think it's because the gap between inner and outer tubing is a bit close they are by no means touching, but in the big radius it must not have as much gap as the starboard side tail because it gets warm. Not so hot that it would melt anything, but its hot enough so that you can't hold on to it for more than a few seconds. It's a small spot a couple inches square and its just the one spot so that's what I'm assuming it's from. I don't have the hot spot of the other tail or any other spots for that matter.

My headers are always cool enough to touch. This is one of the things I regularly check. If closed cooled you may need more pressure. I run around 35-40 on the 525. Service manual says up to 43 psi is OK. This is closed cooled!