I'm not expert by any means with engine diagnosis but it definitely looked to me like it got a little hot by the scuff marks on both intake and exhaust sides. The billet cylinders retain a bit more heat than the cast cylinders do so they need more water flow. I helped a friend put a trinity matrix together with a ss900 engine. We set up his cooling as follows and this is in the south with 90+ degree water temps. 2- 1/2 lines feed a manifold with 4 3/8 lines going out. 2 feed the top of the head and out of the exhaust manifold to pissers, one feeds the spray bar and the last feeds the stinger with a flow control and another pisser. This was with a powerfactor ran wet.
I think your probably right!
So when I first set up this motor I had 2 1/2" lines coming in. One going directly to the manifold and the second I split into 2 3/8 lines with one going to the 2nd fitting on the manifold and the other the pipe and then out a 3/8 pisser. Then I had 2 1/2" lines coming out of the head going to pissers. I'm going to go back to that configuration for sure.
I was hardly getting anything on the temp strips I had on the head or the one I had running horizontal at the top of the cylinder. So I ended up feeding the manifold with a single 1/2 line split to both fittings and changing out the 1/2 lines coming out the head for 3/8 lines going to pissers. And that brought the temps up to what I was used to seeing on my 735. But as I now know thats too hot for these motors. I never would have thought that these billet motors needed to run that much cooler and so I never asked the question of what temp I should be shooting for.
This one's on me. But hopefully my mistake will help someone else avoid running into this type of issue.
Also I don't know if it's just dumb luck or coincidence. But if my case sealant hadn't failed I would have never found this issue and it would have been a whole lot worse!!!