I just switched over to dry exhaust, can I tee my water pressure bypass into one of the exhaust overboard dumps or is it necessary to install a separate tru hull fitting strictly for the water pressure bypass?

I would do a separate water dump.

why do you need dumps?you have water pressure gauges,are you seeing high pressure?

Yes, I had high water pressure before.
I've always run the adjustable bypass and had a separate dump for it, but now I'm running dry exhaust so I wasn't sure if I could tie the bypass into the dump I'm using for the exhaust.

I don't see any issues with tieing into an existing water dump line.

Like griff said probably best to have their own dedicated dumps however I can't honestly see any issues with tying in with exhaust. I'm trying to think of any reasonable reasons why not to and I can't think of any. Another example in comparison is for instance I have to run separate dumps for my merctrans coolers so there is absolutely no resistance etc for max cooling. In this situation here I don't see the importance of other than not seeing the water physically dump. I run cmi's and do have separate dumps for water pressure relief. Just my preference.

My thinking is that only so much water can flow out a single dump.

If the water pressure from the pressure dump is higher than the pressure in the exhaust water, then it might not let the exhaust water exit or could backfeed the exhaust.

Kinda what I was thinking also but didn't know how to word it so it made sense.

Thanks guys, I was kind of thinking the same thing, wanted to make sure I wasn't overthinking it though.