Mike

I did find this website with more information about recommended jetting. It does have recommendations for 240z-280zx. https://www.upgrademotoring.com/performance/mikuni/mikuni_jettingparts.htm

From what I've seen, tuning Mikuni's is a 'process' of its own. When I had mine installed, the guys at Ztherapy had to play around a bit with jet sizes to get them to work correctly. Steve had a small kit (with different jet sizes) and was experimenting until it was tuned properly. My car has a mild cam upgrade and a L28 block. He was able to tune it to work with my driving style. Results will vary depending on what you want to do with the car. If it's a daily driver, you'll use one set. But, if you are racing track, there will be a different set. I don't know where to get the different jets, or even a kit, but, it may be worth a call to someone experienced with the carbs. That said, after the main tune up, I haven't had to touch the carbs since.

Did you check the wiring diagram? Here's the link:

Hi John, glad to see you got it listed. I'm sure you'll find an owner for the car soon. It looks to be in great condition. Here's an image for the front page.