Hi i just got a 94 mustang GT 5.0. I don't what to do to it next. It has cold air, 65mm TB, short throw. My best time in the 1/4 mile is 16.1 in Denver CO. I was thinking about gears like 3 73s or 390s.what would be the best. What else can i do to it that won't break my wallet. Thanks   

If it's stock, go with a full exhaust system first.  Don't mess with the gears, the 94 computer doesn't like any changes with gears.  It will not run like you expect.  In fact, you'll probably feel sluggish compared to now.  16.1 at your altitude isn't too bad.  Pulleys, advanced timing (for altitude), will work.  If you want more, a head/intake swap makes a difference.  Don't fiddle with the cam either.  The computer doesn't like that either.  A set of 1.7 rockers can increase the cam lift slightly and make a little extra power.   

I just got the computer from an 86 to 93 mustang so would the gears, cam, heads, be ok, If yes where can i get a kit like in the Summit Racing Mag. The kit says, Get 350 Horses From Your Mustang 5.0L. But the kit is only for 86 to 93 mustangs. It comes with new upper and lower intake, heads and a cam. What kind of exhaust system would be the best?

You're talking about the Holley Systemax package and it would work on yours, no problem.  You'd have to get the inlet elbow adapter for the intake to work and I believe the cam would work too.  I has .509 lift and is about the limit the computer could take without some electronic tweaks.  The intake is an awesome piece and goes well with the heads.  If you wanted different heads, the AFR 165, GT40X, Trick Flow twisted wedge, and any other with an intake port around 165-180 would do well.  Any larger, it'd be too big and lose intake velocity.  Exhaust would be (for smog) a set of equal length shorties, X pipe and good after cat system.  Go with 2 1/2 pipes, no larger.  You could lose bottom end torque if it's any larger and you'd be set.  This set up should be 350-360 horsepower easy.  I'll have to find out the Pro Flow thing.  I found out they might be out of business but you might could still find the parts needed for the computer. 

Thank You for all your help. So if i gears what would be the best 3 73s or 3 90s.    

Since it's a '94, it won't like either of them.  Ford screwed the computer up on the '94-'95 model and it just doesn't accept anything other than factory.  If it was originally a 5 speed, it probably had 3:08's and automatics had 2:73's.  I would suggest a 3:27 over the 3:73 or higher.  It will feel sluggish and may not run like expected.  This is just my opinion of course but a 3:27 is what I suggest.   

3 27s seem kina small i got a computer from a 86 to 93 mustangs so would higher gears be ok. or would the computer still not like that change. Thanks   

If the computer's an 86-93, then lower gears would work.  The 94 and up computers do not agree with gears.  It has something to do with the what the computer thinks the rpm should be at whatever speed you're going and if it's not, something's wrong and it goes into "limp home" mode.  That's why it cuts out the power and the car is sluggish.   

Thank You. I think i am gaing to get some 3 90s. Do you think I should do that next or do the exhaust first.  

If the computer is in already, the gears would make the biggest difference like night and day.  Make sure you have the speedo recalibrated.  If it's not in, the exhaust.  If you don't mind me saying, the SLP Loud Mouth is a WICKED system.   

Yes the computer is in and i've seen some kind of differnce. Ok than you said to go with the gears, should i go with 3 73s or 3 90s and than the exhust system and i will keep the SLP system in mind. Thank You  

Either one will work really well.  If it's a daily driver, a 3:73 might be better considering the gas now.  A 3:90 would do better if it's an automatic or a weekend toy.  Expect about 500-600 rpm more with the 3:73 and 600-700 rpm more with the 3:90. 

Ok Thank You. I think i run a 15.8 down 1/4 after i put the computer in before i was runing a 16.2 was my best time. What do you think i would be runing after the gears. And yes i drive it every day and it is a 5 sp.   

With a 3:73, you can expect about a 2-3 tenths drop and 4-5 mph more.  4:10, 3-4 tenths and 5-6 mph.   

Ok. So i would be runing around 15. 6 after the gears. Where can i get the SLP exhaust system and is that exhaust system on road or off road, and how much would help me down the 1/4. what else can i do to maybe get into the 14s. before engine stuff. Could i do under drive pullyes, TB spacer, bigger MAF sensor, stuff like that would it help me see 14s Thank You.