Rhythm and Blues

So, this is a giant can of worms I understand that but I'm interested to see what's "working" for most people up here in the Ocean water in the Northeast in the interests of developing a good starting point base line. I've had my Café for a couple months but leave for work every two weeks so I've only had it in a couple times. Once in the lake for a couple hr shakedown, just to make sure everything looked good, then in the ocean for a couple hrs, this is where I'll usually run. So, I don't have a lot of running time data yet. When we ran in the lake about a month ago we were seeing a max h20 psi of 25 but had trouble building any engine heat, saw maybe 100-110ish when "warm". Motors are CMS NA 572-w- stainless marine crossover/bypass, Hardin Marine Cyclone headers, 2"x16" oil cooler-w-out t-stat, all 1-1/4" raw water hoses, Bowtie blocks, Brodix aluminum heads and intakes, drives are Imco Xtream SCs spinning 26p B1s. Its raining today and the boats covered, I'll post the oil cooler AN plumbing sizes when I can uncover it, I'm thinking their -6 or -8. The previous owners ran the boat down in nice warmer South Carolina water and had 3/4" restrictors in the T-stat housings, boat apparently ran 140ish water temp (kinda ideal) so we ran it that way in the lake for the shake down. After thinking (overthinking) about it I threw in a set of SS (drilled 5/32 x 3) thermostats (non High flow) before we put it in the ocean. Everything looked good initially, boat came up to temp and ran 140-150, water psi was 20ish psi at cruise speed 3500 rpm. We stopped for a drink then headed back; about 1/2hr into running back the stb motor decided to get a little warm, I saw 230-240 so we slowed down and I took a look (brought my infrared thermometer), couldn't see any glaring differences from the pt side motor to the stb motor (various spots around the motor and headers) in terms of temps but flow from the tattle tale was less on the stb motor; I thought maybe I got a steam pocket that showed up on the back of the intake manifold where the temp sensors are. Average water psi for me at idle with both the restrictors and the t-stats is between 0-5psi. Water flow in the strainers appeared about the same at idle, and the pumps were the same temp too (Hardin gen 4 SS seawater pumps)
We let the motor cool down then ran the rest of the way up the river w/out any issues but with slightly less water pressure on the gauge on that stb motor. I took the boat to the lake and flushed it, still showed less h20 pressure but I really wanted to flush it with those t-stats in it so I had to get it up to temp and knew I wouldn't have been able to do it on the hose at home. After I got it to the house I pulled both water pumps and the stb motor had one of those Globe blue run dry impellers in it, I had read a lot about these here on OSO; seems general consensus is they garbage, maybe or maybe not but I thought I had found the smoking gun.. I called Hardin and they confirmed all their testing and data for the pumps was taken with stock merc rubber impellers, he went on to say that those globe run dry impellers don't work very good in their pumps and that they dealt with a ton of warranty issues with ILmor because they ran those globe impellers in a big production run of the V10s. Soooo, I installed new merc impeller kits in both pumps and I have gone back to a 3/4" restrictors (out of fear, lol); haven't had the boat back in the water yet, looks like rain for the rest of my life up here... Anyway, I have a set of high flow 140 t-stats in stock 140 Degree Brass Hi-flow Marine Thermostat (drilled with 1 single 1/8" hole) and am wondering if I should throw these in to start testing again? Maybe before that drill two additional 5/32 holes and open up the current one to 5/32 as well. Currently the motors do not have any oil temp gauges (I will change this, have no idea why they don't, seems pretty critical) hopefully I can shoot the oil filter (pre cooler) with the IR gun in the meantime to get an idea of temps. I claim to be no expert what so ever, this is all new to me and would really welcome some constructive feedback. Do I need to run an oil t-stat setup, restrictors, t-stats, circ pump instead of x-over/bypass, psi reliefs at the back of the manifold?.......

Anything you have to say I'd appreciate... Thanks.
PS, I may double post in the general section; hope that's alright...