2003mach1

So I have a 2003 Mach 1 (5-speed)I got in January. Its stock except for I had the exhaust done. I am going to buy a JLT RAM AIR cold air intake here in the next couple weeks. My best time so far is 13.91 at 101.7, on street tires-- So I think I'm doing pretty good for a basically stock car. I am wanting to do rearend gears, and I am thinking either 3.73s or 4.10s.. I still want it to be freeway driveable. The Mach 1s have 3.55s stock so I'm thinking of most likely do 4.10s.. Let me hear your input.. Also what brand of gears do you guys like? Ford Racing? I used to have a 72 El Camino with a built 350 and I put an eaton posi with Richmond gears in, and I liked the Richmonds... Let me know.. Thanks,
Brent

NeoTokyo

I hear a lot of people are happy with their 4.10's but the general rule for the Mach1 is 3.73 for a 5spd and 4.10 for the auto.

Personally I will be running 4.56's when the car is done.There was a NA 4V shootout in MM&FF a while back and almost all of them had 4.56's, there were guys with common bolt ons and those gears passing into the 11 second zone. The winner was Boss330 Racing with his 5.5L stroker, but we all cant afford a Ford GT 5.4L aluminum block He could have gone deep into the 9 second zone on slicks. He only got 1 pass in because of a mysterious ticking in the valvetrain. The runners up were running stock bottom ends with ported heads, FR500 .472" lift cams and bolt ons and a couple were in the 10's with 4.56 gears.

It was a great article, I can see if I can find a .pdf for you.

-Eric-

Colorado_Mustang

The Mach I's engine loves to rev. 4.10's will be pretty good, and even 4.30's would work well.You will run into traction issues, however, so keep that in mind.

Most here will recommend Ford Racing Performance Parts.

I like the Richmond's in my '71, but they are a bit noisy for some.

NeoTokyo

I like Pro5.0
They backcut their ring gear taking off un-needed weight and freeing up a little horsepower, they are also beveled on the gear edge and polished, so they are just like FRPP but they are backcut

2003mach1

Thanks, its nice to hear other peoples input.. I'm probably gonna do 4.10s... Either way I need slicks, The way it sitsnow its hard to hook up at the track..

mustangman02232

4.10 auto/3.73 5 speed, whoever came up with that needs to be shot

4.30s in a 5 speed, 4.10 auto,

NeoTokyo

mustangman02232That is a general rule of thumb when it comes to having a car setup so that its fuel economy isnt greatly affected. You need to be shot, not me.