351 rebuild help

[Rookie351]

Hi guys, first forum post ever! I'm a Queenslander and I just bought a 351c it is in an xd fairmont I plan on rebuilding it to put in an xw. I want 500hp as I have been told that that's as much I could go on a 2 bolt main and I can't really stroke it as the journals are weak. I just want to know if 500hp is achievable out of this engine or am I better off looking for another is only cost me 400