3.73's or 4.10's???
 

ok i went to the track tonight and concluded i need gears! i ran 5 runs, first and worst was a 15.45 at 88.72mph. my best run was a 14.97 at 94.67mph. my 60ft times were all around 2.22 or so. my top end was great, but the low end was bad. now i want to get gears to help my launches, but don't know which ones to get? keep in mind this car is a daily driver and i don't want highway RPM's to be really high if i get 4.10's. but i do have an auto and am in need of some kick! what do u guys suggest, and how high do u think my RPM's will be if i get 4.10's?
Thanks all!!!

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89 GT AOD w/ shift kit, B&M rachet shifter, Trickflow intake, Crane (E-type) cam, 70Tb, 75MAF, 1.6 Rockers, Pulleys, MAC headers and H-pipe, Dynomax mufflers, K&N, 3 core radiator, white face gauges, custom interior, cobra R rims
89LX 2.3 Notch, daily beater!
MY89GT

My old 4:10 AOD(No convertor) 3600 lb Cougar 14.2@97 on 14" street tires. 2250@60 mph. You can use the calc. here to figure rpm's out.

I would recomend 4:10 for U, but if rpm's concern you that much get 3:73.


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82 Mercury Capri 302, Comp. Cams, Tremec 3550, 3.73's, 12.8@106 N/A
Kevin's Capri
Kevin's Mustang

Most of the auto guys say to run 4.10's

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79 hatch w/ NA 347,stage 2 Canfield heads, out of the box Victor 5.0 intake, solid roller cam, Aeromotive fuel system, proshifted TKO II.MY CAR http://www.mustangworks.com/cgi-bin/...splay.cgi?1288
93lx all stock + tremec

If your car is a daily driver and you do alot of highway driving I wouldn't go with 4:10's or 3:73's. They will kill gas mileage and the high RPM's will get annoying fast. I would recommend 3:55's for the following reasons:
1) gas mileage IF you drive alot on the highway
2) if in the future you want to throw a power adder on you will be LESS likely to blow out the rear end or blow you out of your optimal power band
3) since you should already have 2:73's you will notice a considerable difference in launches with 3:55's

My car is a bit heavier than yours and I have no problem smoking ( off the line of course)Cameros, Impalas or pretty much any normal vehicles out there form a stop.

Also i recommend a shift kit to help improve your shifting. My buddy has a 97 Cougar and it did wonders for his AOD. Again just my thoughts on it all. I could be wrong on most or all of what I wrote but its what I have seen first hand. http://www.mustangworks.com/msgboard/biggrin.gif

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94GT Vert, 2-chamber Flowmasters, Headman off-road h-pipe, Steeda Tri-ax short throw shitfer, Mach underdrive pullies,FMS 3:55 gears, MAC cold air induction kit, Steeda, subframes w/ crossbrace, Sumitomo 245/45/ZR17's upfront with 275/40/ZR17's in the back, MSD 6AL w/ Blaster 2 coil, Battery relocated to trunk.

IMHO 3.55s are a waste of money, my car used to be an AOD and i wished many times that i would have gone to 4.10s instead of 3.73s, i suggest either getting a 2800-3000stall converter and 3.73s or if you dont have the money to do the converter then get 4.10s, y the way about mileage, i got about 22mpg on the highway with the 3.73s, so dont ke4gde's idea of gas mileage hold you back

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88 Notch, B&M Ripper, 3.73's, Ported E7's, Explorer int. w/ ported lower, pulleys, 1.7RR's, BBK headers, off-road H-pipe, flowmasters, subframes, 65mm TB, March ram air ,MSD coil, U/L control arms, 155lph f/p, Crane Adj.FPR, Nitto drag radials, best 1/4--> 13.76@101.4 on a 2.17 60ft

4.10's if you plan on keeping it an auto. And change the stall as said above.

E

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1991 5.0 LX Coupe - 38,000 miles

13.17 @ 106.14 mph w/ 2.138 60'

I wouldn't recommend 3.55's for an AOD. I'd say go w/ the 4.10's unless you're not worried about highway driving and are not gonna add any power adders.......then, I'd go w/ the 3.73's!

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'90 LX 5.0;12K original miles (no sh*&);3.55 gears; March pulleys;Edelbrock Performer Heads;BBK 1 5/8" equal length shorties;MSD 6AL ignition w/ blaster 2 coil;FMS E303 cam;Pro-M 75mm MAF;BBK 70mm TB; Eibach drag-launch spring kit;Southside welded subs;9" K&N cone filter charger;Hurst shifter;Cervini's 3" turbo hood;A/C delete; gutted cats;2 chamber Flomasters;Corbeau racing seats;FMS 30# injectors;JMS chip; Holley 190lb fp;TFS track heat Intake (12.299 @ 113 - 1.78 60')

Before you even do gears, I would buy a non-lockup stall converter. It will raise your stall and make a VERY noticable difference. Look at the times of my 91 (sig.). That 14.71 was with only a stall converter and 3.73's. My 60' times were always in the 2.10 range.

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91 GT AOD: 14.71@91.78mph
SOLD!!
01 GT 5-speed on order:
Released from Plant, awaiting convoy to dealer

I put 4;10's in my baby 1 yr. ago tomorrow. Ilove them, my car suprises many a 5 spd. I did the shift kit 2 wks before that, these are very good choices for first mods IMHO. I am now gathering parts for a T-5 swap as my AOD P.O.S has taken the big plunge. 3 yrs on rebuild and i dont plan on doing again 3yrs from now. Look into Bauman's shift kit as I am not to happy w/ my transgo. It'll shift into OD when in D alot of times. I explored Lentech and a few others and decided the swap is cheaper for me, since i have a lot of the parts being donated to the cause. Oh BTW @ 80 mph on 245-50-16's I'm running 2900 rpm w/ 2 chamber flows and rear seat and sound deadning stuff removed from behind the seat it is not that bad. John

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89 Notch: ASP Pullies,
K&N Air,Transgo shiftkit,Trans. cooler,FMS 3 core , FMS 4:10's, 1.5" cowl, cold air kit, hooker shorties(jet hot coated), O/R H-Pipe, ASP solid mounts, Energy Sus. Trans. Mnt. BBK 70mm TB, MSD 6al, Dual elec. fans, 5.0 Firepower Kit, Scorpion 1.6 RR's, Flowmasters, 73 mm MAF, cobra intake and crower #512 cam,

[This message has been edited by John (edited 09-21-2001).]

4.10 4.10 4.10 4.10 4.10 4.10 4.10 4.10 4.10 I'm putting them in my T-5 GT very soon. That's why we have a fifth gear.

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Todd
1995 GT/T-5
Pulleys; 65 mm TB; Flowmaster cat-back; Mac off road H-pipe; FMS aluminum driveshaft; short-throw shifter; HD clutch; Cobra R's; Cobra front and wing

I have 3.73's. I chose them over 4.10's because I plan on eventually adding a supercharger and I felt that for the power expectations, 4.10's would run through the gears too quickly. I have a Lentech AOD w/2800 stall non lock-up converter. At 6000 rpm on my factory tach in third gear I am going approx 110 mph. I have heard if you are going to stay N/A, go with 4.10's, If you plan on forced induction, go with 3.73's or even 3.55's. I know a guy with a 90 lx convertible that has 3.55's w/AOD and Vortech S-trim w/aftercooler and I personally think his setup works perfectly. He runs 12.1's @ 119 mph on radial's!