The 400 service delivers 320 continuous. The AC loads up a lot when it comes on, and you said there were two. I read welder and some other non-hobyist-type tools in the shop. Add the tech from the graphics business (computers, monitors, printers, plotters)...

Don't take my word for it - most power companies offer 100-, 200-, and 400-amp service. I'll bet my bobbysocks they recommend the 400 service to Jake. Our place in P'cola wasn't huge, but when we added the heat pump for the pool and the outlets in the garage, we had no choice but to upgrade from our 100-amp service (1960s house). The difference between the 200 service, which we would have maxed-out, and the 400 service was surprisingly small.

I miss that house.