Need some Pointers with my setup

[White87GT]

Well, here is my setup, its an 89 LX with an Carbureted 302 in it, I have a Holley 750 carb, Edelbrock Torker II intake manifold, E-303 Cams, Ford Racing Catalyctic H-Pipe, American Thunder Cat-back, it has 2.73 gears right now.

Heres what Im looking for, I definately want closer ratio gears, but I dont want to kill my gas mileage, pretty much everyone has told me to go with 3.73 gears but no one can give me any idea of what thats gonna do to my fuel economy, I know switching out the gears is going to make a noticable difference pretty much no matter what, but would 3.55 gears be better for my setup or should I just suck it up and get the 3.73s and say to hell with the fuel economy? Oh yeah the trans is a T-5...and what kind of performance gains am I looking at after I switch gears out?

Next up, Im not sure whether I want to go with LT headers or shorties, any pointers/opinions here would be greatly appreciated, I also want to replace the h-pipe with an off-road one and replace the mufflers with SLP Loudmnouth's or MAC ProChambers.

What kind of power should I be making once I get all this done? Oh yeah any opinions or pointers in any area of my setup are welcome and appreciated, this is my 3rd mustang (96GT, 87GT before this one) and so far it has had the least problems and I finally have enough money to devote to it, both my previous mustangs had some severe body work dmage that ended up costing too much and the 87 had some horrible transmission problems. So far with what Ive put into it this one is the best, and Im looking at spending much more time under the hood doing my own work which is why Im glad its the carbureted 302 it has proved to be a very easy engine to learn how to work with.

 

[90mustangGT]

That is a big carb for that setup. People often go way too big on carbs, a 650 would be enough, 600 would probally be ideal. I am no expert though.

A 2.73 gear sucks, even on the highway with a OD tranny, makes 5th gear a dog. A 3.73 gear would really wake that car up, be sure to go ahead and rebuild the traction loc. Gas milege isn't effected that much, some, but not like some people say.

Longtubes all the way, they show more power, especailly in the midrange. MAC seems to have a lot of interferance problems, I have BBK's and they work and went on great compared to the horror strories I have heard with MAC's. Shorties will show little gains, especailly with stock heads.

A better mid-pipe will really help. PC, X, or H, it's up to you. The X seems to be better for upper rpm and has that raspy sound, H is usually better for torque and has that muscle car bark sound when you get on it, and the PC seems to be a go-between, sounds good to, echo like sound.

As far as "how much gains" I can't say but they would be there, I promise.

 

[White87GT]

I have the carb Jetted down right now because 750 is definately too big for my setup, but I wanted something the car could kinda grow into as I put some more mods into the engine. Im not going all-out ballistic with the engine I just want a nice street/strip car that can stomp on the car around here.

I love the sound an offroad h-pipe has but Ive been thinking about the X pipe a little more, because Im set up for more mid-range to upper rpm power. Thanks for the advice, good to have confirmation on how much it affects my fuel economy.