3:31 gear for my factory PP gear

Someone with similar mileage to my car wants the 3:seventy something gear from my PP s550 and he wants to trade it for a 3:31 from his car, i think this the non PP gear. My car is boosted and suffers from lack of grip. Is this something that is going to benefit me in any way or should I pass on the trade?

You'll miss the pull of the 3:73...keep em and get tires or a suspension mod for better traction. ..not much diff in mpg I hear.

Depends on what you do with the car and what kind of boost you are running. Most boosted guys go to the 3.31 with a manual and a 3.15 with the auto.

Stock boost on roush TVS, manual and it is my daily.

I enjoy the 3.55:1 in my base 16 GT. Keep the 3.73:1 and do BMR CB005 & 006, vertical links will help too. Sticky tires R888 or treadwear rated at 240 or less will grip better.

I think 3.31 is a great for the gearing in the manual transmission. 1st gear is just too short.

I like the 3.31 gearing in my car with the Whipple. I still short shift 1st most of the time and still have traction problems in 2nd WOT stab. If I ease into it will hook pretty good in 2nd with 325 conti dw's around 30-32 psi hot.

I have the NT555 G2s at 35 to 36 psi hot and they don't hook at all on 2nd. What psi cold do you have? 28? your Whipple is most likely making more hp that my Roush (dynoed at 640 - 650). I think there is a chance I may benefit from the gears but I may benefit more from the BMR suspension mods Coyote Red suggested above. Is that the case?

I'm glad I moved to the 3.31. The car is more manageable now. I race my car anyway, so I needed the extra gearing which is why I changed. Depends on how much power you're making.

Barrel said:

I'm glad I moved to the 3.31. The car is more manageable now. I race my car anyway, so I needed the extra gearing which is why I changed. Depends on how much power you're making.

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My car is making between 640 and 650 hp on the dyno.

fcarpio said:

I have the NT555 G2s at 35 to 36 psi hot and they don't hook at all on 2nd. What psi cold do you have? 28? your Whipple is most likely making more hp that my Roush (dynoed at 640 - 650). I think there is a chance I may benefit from the gears but I may benefit more from the BMR suspension mods Coyote Red suggested above. Is that the case?

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Yes when playing around with the car it is around 28 psi cold. I get better mileage though running around 36 psi hot. Tire pressure makes a pretty big difference in traction.

Suspension mods help greatly with putting the power to the ground I would suggest CB005 cradle lockout, lower control arm bearings, and vertical links for your power level.

I'm attempting to see if anyone in my area is interested in this swap.
No one has taken the bite yet, but I would rather have the 3.31 gearing over my 3.73

Obsol3te said:

I'm attempting to see if anyone in my area is interested in this swap.
No one has taken the bite yet, but I would rather have the 3.31 gearing over my 3.73

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Keep an eye on Shelby auctions on Ebay. Every once in awhile they will have take out complete differentials from their Shelby builds with low/no miles.

i have 3:73s i was thinking on going the 3:31 route but for what i do the 373s are fine spirited driving and 3rd gear pulls and all 373s work for me . i know a lot of s/c guys change over.. guess it just matters what your doing with the car .. personally i love the feel from 2nd gear up with the 373s..
and your going to have traction issues even with diff gears unless you run a drag radial or a really sticky summer tire.ive done some suspension stuff and it helped a good bit.i still need a few more pieces though

In a 1/4 mile run you'll only need 4 gears to trap with 3.31's.