You make it sound like he wont gain anything. He will just not as much as a l67 would.
I say mod the n/a with supporting mods for a l67 then if you want to go boosted your not in the hole $ wise.
What I stated is fact, the law of diminishing returns... You can spend $1k on adding 30hp, and if that floats your boat, have a go at it. You could also spend the same and add 100HP : )
Enjoy your day!
Overkill BBC Cam, YT 1.8 RR's, Rhodes Lifters, STGII Heads, GenV, Pacesetters, 3" Exh to Tips, TEP Trans. N*, ID 75# injectors/E85 coming soon