Looking to make Real power without Forced Induction

trickflow heads are a nice upgrade while your at it if you have the coin

Trickflow heads (38cc), aggressive cams to match trickflow heads, headers, midpipe, bigger throttle body, and a tune can give you roughly 330 rwhp range on a stock block.

Personally instead of the N/A route - for real power - I’d go with a supercharger, turbo, or nitrous. Better drivability and bigger gains for buck.

Full exhaust (LT’s and midpipe of your choice) and a set of cams always sounds good. I ran full boltons for a while (LT’s, midpipe, cutback, intake, TB, intake plenum = 260rwhp) and then added cams to make 289rwhp. Full boltons had the best drivability (smooth like OEM but with more power). Cams added more on the top end with a little sacrifice to drivability (lope is fun but every now and then I killed it at a stop light, hehe).

Finishing off all the boltons (LT’s, midpipe, intake plenum+ 75mm TB) will probably cost about $1200. Most will need help installing the LTs. I’d use stage 8 locking bolts for the headers and new gaskets to prevent leaks.

Comp 270’s are popular for their lope. I’d budget $2000 for a dyno tune, handheld tuner, springs, install, and cams (~1600 if you can do the install yourself).

I’ve been down that road - if cost is a concern but you want the most power, I usually recommend forced induction now a days if you plan on keeping the car. The price / hp is way better. If sound is your priority then about $3200 will get you a nice sounding mustang.

TFS heads + intake, cams, bolt ons as previously mentioned.

More NA power? 5.0 big bore block with more compression and maybe a stroker kit.

Or you can just pop a centri supercharger on it and be done.