I think you’re going to be (IMO at least) 20 hp short with the 1408 cam and stock heads. Referred to the Mopar crate engine for guidance. They listed as a 380 horse 360 with a larger can and a single plane. I wouldn’t use the single plane since the RPM will perform as well with a lot more torque. But the camp or the heads. Didn’t say what size to run. Mopar ran their crane three 8360 with one three-quarter headers.
This engine with a hydraulic roller cam of 230° at 50 for the intake is notorious to 400 hp or better consistently.