5.2/5.9 H.P build guesstimate

Sup guys, so this is my new build I have a cheaper way of going with a ready core 5.2 magnum in my yard, or just find me a 5.9

Car is a 67 Abody, manual steering brakes, 904 trans go shift kit 2800 stall converter 3.55 and 3.91 gears available. Long tube headers Rpm Air Gap and a 750 Holley Vacuum secondary

Camshaft I have a used Howard’s grind, .503/533 lift @50 221/225 intake 274 exhaust 278

Two questions, will this work well with my 5.2 block or should I source a 5.9?
Also how much H.P are we looking at, trying to get in the 375-400 Range lol