Explain "fishbite roughness" I've never heard this term before.
For curiosity sakes, do you have a temp gun to see what temps the manifold is at or exhaust?
I would find a Denso unit - Interchange #471-1256.
I would not use one from Four Seasons. We've had nothing but problems with them at my work. The factory one is still available, but at nearly $1k, not exactly cost efficient.
I had my old ecu done but I don't remember where I sent it it to. If you're handy with soldering, maybe try one of these
- https://www.ebay.com/itm/235914903157
https://inovauto.com/hondaimmo-1.html...
Yes, you should hear 1-2 clunks as the TC (torque converter) seats itself into the transmission. It should sit relatively flush with the case of the transmission. Sounds like you got it correct the second time.
I would email them for verification of fitment, maybe they can possibly swap them out for you. You may have to run an aftermarket fuel rail or spacer/adapter to/from rail and intake manifold. I know people used to run the RDX injectors and they were 410cc(?) I think.
I would also probably reach...
See if someone can 3d print one for you. I know BigCartel does a lot of stuff for the late 80's/90's Hondas. They might be able to come up with something.