I just did business with john at caspers this morning, concerning a engine harness ,,,he really went out of his way for me ,,,complete customer satifaction...
I have a harness I used on the engine dyno, it was built for the FAST XFI. Don't know if you need an XFI harness or not, but I would be willing to let it go at a reasonable price if you think you could make it work in your application.
He has specifically for Regals or can custom make one for your needs. Just need to give him a call and talk with him.
I'm sure the price scares some away, but who else makes them? How much do you think it would cost if you could get one from GM these days?
I will be ordering one soon myself from Casper's as I'm working on restoring a GN. My engine harness was not that bad but I figure I rather have a new one as to not have to worry about electrical gremlins for quite some time!