Check out this thread if you haven't already done so. Tons of good info.

oil pressure problems from stock hardware

Another possible issue I saw in the above thread is if you're running a high volume oil pump and a oil bypass in the block adapter you can get into bypass mode at high RPM bypassing the cooler/filter.

I don't think that it is the filter pad itself that is restrictive, but its the fittings/threads on the inlet/outlet that are a choke point.

When I plumbed an oil temp gauge into my oil sump, I almost wish I didn't do it. It became this obvious potential issue of climbing oil temps.

Good oil temp management starts at the oil passages, and making sure they are rounder off and free from sharp angles and obstructions where you can. It all helps out.

I bypassed the thermostat on the port engine and the temp never even got to 210 degrees so I'm confident the coolers are working. Most of the day was below the 190 degree mark. If just idling for a while it barely cleared the 140 degree mark. I had my wife with me for a fathers day cruise so no WOT stuff but we did cruise the river at 3500 for a while and out on Lake Michigan I was running at the slowest speed I could and stay on plane which turns out to be about 2200 rpm. Anyway, I do need a thermostat and these are the choices.
FSM-185 185ºF (85ºC) 180ºF (82ºC) FULLY OPEN AT 203ºF (95ºC) Engine Oil (Street & Strip)
FSM-205 205ºF (96ºC) 200ºF (93ºC) FULLY OPEN AT 221ºF (105ºC) Engine Oil (Street & Strip)
It's the "fully open" number I failed to notice when I ordered the 215 degree thermostat's I have. They fully open at 233 degrees.
These all have the same housing so I plan on just buying the rebuild kit in the temperature I want. I am leaning towards the FSM-185. Any thoughts or reasons to go with the other? Thanks for your help.
This picture shows the warmest reading all day and this was after a decent amount of time at 3500 rpm.
Just an observation that I had completely backwards. We stopped while on the lake (idling in neutral) to test the water (still very cold) and the port engine with the cooler oil temps had steam out of the exhaust. I always thought that the steam was from the hotter engines. Both engines were running the same water temp all day.
Again, thanks for reading and your input.

Again, thermostat sets the MINIMUM temperature. Why would you want that to be 185 degrees? That's not hot enough to be confident about boiling off moisture.
I would choose the 205. Water boils at 212.

Thanks Doc for your input. I had "back and forth" emails with the guys at Improved Racing and this is what we decided on.
The thermostats I have (215's) don't fully open till 233 degrees by design (again I thought fully open at 215. My mistake) and my oil temp went right on by that during a WOT run so these 185's fully open at 205 and my thinking is that when my oil temp runs over these that it stops somewhere between 215 and 230. Don't know where it will land as it "averages out" but my hope is that its hot enough. I'm not made of money but I can swap out the internals of both of them for under $40 so if these are too cool I will buy the next ones up. If they still run too hot they have a 165. Won't know till I get them installed. Thanks again.

If they fully open at 233f, they aren’t causing higher than 233f temps . Something else is.

SB, I don't care for your logic 🤔

An oil thermostat is used to warm up the oil not to cool it. Just like a water thermostat in your car.

I get it. Max oil temp has nothing to do with the thermostat. I guess ill just see if it helps being fully open earlier. The coolers based on the temps while bypassing the thermostat seem to keep up. More influence on temp with an earlier start.