No, sadly, I haven't solved it. I've got some ideas for this coming year and how I'll go about attempting to resolve the overheating thing but if I'm honest, we've (wife and I) shifted gears, got her a new daily and am looking at turning the Outbean into a new project. Tentatively, the plan is to swap engine/trans like you did, clean up the interior and exterior and let it go.
I want to see the overheating thing threw to the end though. Not just for myself, but for the community. Maybe it's foolish, but we've only got a few more things to try (rad and another key element) before we're going to be forced to admit it's internal or otherwise out of reach unless the engine comes apart and gets torn down--something I plan to do if we can't resolve it.
If we fix or remedy the "overheating" I still plan to pull that engine out regardless, so.. yeah. We'll see how things pan out and how the weather cooperates, or doesn't, with the timeline of me getting around to that project.
Out Standing being willing to do the job to resolve the issue so its known here! A truly Magnanimous gesture! I hope you find it. I am still interested in knowing.
One thing I never mentioned when I did the swap... the vacuum connection (for brake vacuum) on the JDM motor I installed is on the passenger side and while there is a squared headed plug on the left side, closest to the vacuum assist on the brakes, I could not get the plug out... I was afraid I would break the intake... so I just went with a longer line to the other side of the motor. Just an FYI...
Sorry so long to reply. Sorta scrambling here... got notified that I am getting furloughed from my current part time teaching job... Covid-19 hitting hard everywhere... It was a total blindside.... was told multiple times no worries, money is there, we will all be paid etc, etc... told that as recently as last Wed, 4-01-20. Guess it was an April Fools day prank, They told some 10 of us, on Thursday we would no longer get paid... still have a job, but no $$.. No one was laughing. But... I think we (my family) will be ok. I can maybe pound a few more nails, or turn a wrench for some $$...Sad thing is I think the school may have to close. I Filed for the doll...I never had to do that, I paid in for 45 years might as well get some back. That will help at least for a bit.
So I still plan to pull the plugs from my old motor and see if any are steamed cleaned indicating an bad head gasket... I will report back. I will have the time now. LOL....johnre and l lucky texan suggested doing this, it will be good intel for me too.
Looking back at your pics @aesthetic.rake I like that engine stand you have.. bet it rolls easier than mine... my engine hoist does not move well at all under load.. do any of them? LOL