360 Rebuild Horsepower Potential

Yeah, there's a ton of variables missing. I would be more conservative given you're not providing info on the level and quality of machining or other parts. I'd put it around 325hp at the crank. If the short block and heads are blueprinted, and performance quality work and parts are used, and the exhaust is headers and a good system, and the carb is close to right, and you can tune, it should be stronger.
It does look like a good street performer. The abilty to cruise and lay some rubber. I did something similar with the wife's 360 compression/cam wise. Same slugs and a Hyd. roller of about the same duration. It needs gears though. ith the 3.23's, it is slow out of the hole but it does run really well top end. Top speed is good. I had the car to 130 the other week.