Intercooled turbo with boost controller to bring boost on low - if you have no smog laws. Add some water/methanol injection to that plus tune with more timing. If you choose the right water/methanol injection kit and set it up right, you can bring on more timing at a lower RPM. timing is where you get HP in a tune, more so than AFR. You have to back off the stock timing with FI anyway. An intercooler gets you some of that back. WMI gets you more back. Get that tune for higher octane gas too, like 93 or 94 if it is readily available. Yeah, V8s are cool too.