Well by "finding" I assume you mean to free up power instead of adding to it. I don't know how many of these things you'd actually want to do for a street, daily driven car, but I'll try and prioritize by the ones that wont' affect streetability too much
1. K&N? (real small, but as you said it adds up)
2. carb spacer (I'm sure you can fit one with your hood)
3. electric fan
4. remove PS
5. electric water pump (I've heard it's not too dependable when you put a lot of miles on though)
I don't know if you already have these things considered and have them optimized already, but if not
1. have carb tuned
2. bump timing
3. plug gap?
And of course, any weight reduction will "free up power"
For "nearly free" hp, I've consistently seen good old fashioned tuning make significant improvements in hp and overall performance, often 20-30hp from a well running but under performing engine. I used to regularly tune the 302/2V in my Mach every weekend. This proved itself every time as I was able to get 20mpg average and run nose to nose with Fox 5.0s... all with stock single exhaust, FMX tranny, and 3.0 gears.
What to do? Start with good tune up, including new cap, rotor, wires, and plugs. Then correctly set up your distributor to provide the "right" advance curve. One of the big magazines ran an article on doing this in the last year. Next, set the timing to provide as much initial advance as possible without causing detonation. Then tune the carb. There isn't much you can do with a stock Autolite, but if you've got a Holley, get a tuning book for it. Change the jets, power valve, accelerator pump, etc. Read the plugs to check if its rich or lean.
For not so free, but generally inexpensive, the stuff NorCal suggested is good, especially an open element quality aftermarket air cleaner and K&N filter & carb spacer. Also, if you can rig up a cold air induction setup, that can also offer a bit of power.
Then for not-too-outrageously expensive mods, headers and a good dual exhaust can be the best source of hp, usually between 20-40hp over a stock manifold single exhaust. This actually can be the most cost effective, because it can easily be done for total outlay of less than $400. $10-$20 per horsepower ain't bad.
Windage trays bolt on horsepower! By preventing the oil supply from splashing against the crankshaft, this neat item will give your Mustang an extra 10-15 horsepower without sacrificing gas mileage like you would with a bigger carburetor! Plus Canton's superior one-way screen design allows residual oil to flow freely back into the pan while preventing horsepower robbing buildup and backsplash! never used one but it sounds like it gets the job done. this Canton windage tray kit goes for $119.95. As for carb spacers, you might find a horsepower or two in some cases, and you can move the power band around a bit and help distribution in other cases. And If you have the money exhaust is also an option. Here is what NorCal answered for me about exhaust:
"Mufflers: Well...I'm gonna go ahead and be the first to vouch for 40 Flows. Yes half the musclecars and muscletrucks on the road have em, but in my opinion they simply can't be beat. I lucked out in the fact that somehow there's only one other person in town with em (loud ones atleast). They sound awesome, deep, rumbly and metallic at idle and scream at WOT.
Headers: If you're doing full exhaust I'd definately recommend headers too. Different headers will give you a different sound, hopefully someone will chime in on exactly what they are... longtubes cut down on drone and produce a quieter idle and louder WOT i believe.
Pipes: Based on your engine performance, the wilder, more powerful the engine the bigger the pipe... (anywhere from 2-3" as far as I've heard). Smaller pipes give more torque and backpressure and bigger pipes let the air flow better at high rpm. Smaller pipes also tend to sound more crisp while largers are louder and hollower.
Crossover Pipe: H for chambered mufflers, X for straight thrus. H for more of the musclecar sound, X for the Euro sports car sound.
Tips: Turndowns are louder and "mushier", tailpipes are crisper.
Keep in mind that your exhaust not is greatly affected by your engine. Heads, rockers and most importantly CAM are all going to make your car very different. No matter what exhaust you have, you aren't going to get the mean lumpy sound with a stock cam."
I'll second or third the exhaust recommendation. You can get a set of tri-Ys cheap that will really wake up a stock small block. Add to that a true dual job from your local Midas/Meineke and you're gonna see a real 15-25 HP jump from a few hundred dollars.
One thing I must say about the flowmasters...they sound great but at higher rpm all my buddies w/ them complain about them sounding like they get quieter. None of them scream at WOT and that's with some of the following setups: LT headers, mufflers welded to headers and thats it. LT headers, 3" pipe into original 40 series, and the same as previous except 2.5" pipe. They sound awesome idle to low rpm but I dont like them at WOT. Performance wise I'd really go something other than Flowmaster...nice sounding but compared to alot of others thats it...sound...there's a nice selection of other nasty sounding mufflers that not only scare small children but offer more power gains. Magnaflows would be a choice above flows in my book or even Mac Flowpaths if you just want that sound. Spintechs seem to be a pretty nice mufflers, Borla, etc. Just start going to exhaust sites and look around, compare dyno sheets if available.
I will be a little different from the crowd. I have my own ideas that don't always follow the 'beaten path'.
Generally speaking, I like your combo alot.
The C6 is sapping alot of power and throttle response though.
Carb: Go a little more aggressive... 3310 Holley, then supertune it. I won't go into the process here, I will say get a book on it and read it over and over till you get it. You won't regret.
Intake: That one is crap, especially for a heavy auto tranny. I would highly recommend that you don't go with a dual plane either. Your gearing and cam are more than sufficient to allow use of a mild single plane, just not the one you have. The runners are too short and the plenum too big. Very poor design. Save some bux and shop for a used Torker 289, Holley Strip Dominator, Wieand X-Cellerator, or Offy Port-O-Sonic.
Your exhaust sounds perfect. The Tri-Ys would not flow on par with your intake or cam IMHO.
Your gear is less than I would use with your combo, but still very functional. I am partial to 4.11s (hence my name), but anything between the two ratios would suit.
Run a cooler thermostat.
Run the hottest plugs you can without detonation.
Electric fan is best, but flex frees up a little power.
If you don't run much electrical in your car, a Moroso alternator pulley.
MSD 6 or better.
Electronic ignition, stock magnetic trigger is great. Don't do gimmicks like Unilite.
Large diameter Ford distributor cap. Prevent crossfire and gives you HEI style posts.
Block off the heat riser to the intake.
Insulate the carb. Either with a plate or phenolic spacer.
K&N air cleaner. Also use a free flowing housing like the Moroso drop base design, it takes turbulence from the airflow and directs it into your carb.
Aluminum driveshaft. (Aerostar vans used them and they convert fairly easily from what I have heard)
Lighter rims.
Any lighter parts that are rotating or unsprung weight will add to the power you get to the ground and the responsiveness of your car. That is why the C6 hurts, but if you like it, then lighten other stuff behind like the rims and driveshaft.
The jist of it though is to get into a better intake and carb. Then supertune it. After that you won't have to touch it for a long time, and if you do, you will automatically know what tune it likes.
Good luck
Dave
Sorry so long.
Wow, just noticed...
Fort Walton
Do you get over towards P'cola much?
I get that way quite a bit.
If you have been in P'cola much, we may know alot of the same Ford people. We have some real Ford phenoms here in P'cola...
Jessie Holmes (SBF and Clevor guru)
Bob McNeal (Mustang Village)
Donnie Culbertson (Speed Unlimited, 351C guru)
Gene (Gene's Transmission)
I am leaving some out, but you get the idea.
Are you coming to the big Ford show at University Mall next month?