350-400hp budget build 360 ideas???

No doubt. That would be the first or last thing to do. Because of expense. Considering that if your starting with old greasy heads, the price in total could very well be $2,000 from start to finish. I don't care who or what site price list you point to. By the time you take off the head and get it back on the engine, it'll add up real fast.

Cost of shipping to and fro, cleaning up the head from degreasing to machine work on the deck side, (Clean up cut) gaskets, new valves and relateed hardware up top matching the new cam. All I hear is ka-ching - ka-ching - ka-ching....

All left over monies go to cam, intake, and headers into simple straiught tubeing and mufflers and cheapies at that to stay under budget. If even possible.