hey guys i have a basically stock 1993 mustang and trying to find out how much faster I could get in the 1/4 mile with 4.10s and what kind of increases could i get with a b&m shift kit.
my convertible went from a 15.8 stock to a 14.7 by just changin gears and adding a shift kit.
then to a 14.4 with a five speed swap.
I'm running out of gear at the end of the 1/4 mile though...
So keep that in mind. if you plan on modding your aod heavily please go with 373 or 390s. otherwise you'll be redlining by the timing you cross the finish line.
My friend, who still has the aod, redlines at 103mph, so he's stuck there..
i cant tell you exactly how much you will gain but my car dropped .7 and picked up 2mph from a torque converter and gear change (2.73s to 3.73s)...id say atleast 3 to 4 tenths dropped in the 1/4. The guys that have already posted are right about the car being at 6000+rpm going through the traps. You can either go with 3.73s and run a 26in tall tire or do 4.10s and a 28in tall tire so you're not reving that high.
4.10s are fine you can break in the 12's with stock h/c/i but thats about it i was turning around 5600rpms @ 102mph 12.8-12.9's
4.10's .5-.6 second
good shift kit or vb .3-.4 second
good converter .6-.7 second
stay away from b&m products except for there stacked tranny coolers
i would go 4.10's for car 3400lbs or more.3.90's for 3200lbs or 3.73's for 3000lbs
RPM's are way off on the stock tachometer.. So you can't trust what it says while crossing the finish line. Only way to truly know what your trap-crossing rpm is with an aftermarket tachometer.
Taken from the Chambers Racing website, you can use the formula to determine what RPM you were actually crossing at if you known your trap speed...
gear choise depends on rpm range of mods and weight of car. my suggestions earlier were based on the stock h/c/i combo that will peak power at 5000rpms
I'm having the same dilemma also. Currently 302 is stock, aod w/ PA valve body. I have a 351 that hopefully I can get in over the winter. I'm stuck on 3.73 or 4.10. This is a daily driver that will have some days at the strip. I'm getting all different answers. I know alot has to do with the whole setup of the car, but I'm not understanding the reasons for either gear. I hear so much that with 4.10 you'll run out of motor, but then I'll hear that with the 351 it won't matter.
Oh also, if thinking about a B&M shift kit, please think it over. If you can spend the extra money, just buy a new valve body!! Yeah a shift kit may only cost $60 compared to $200+, but it is worth it.
what you pickup will make a big diff based on your current gear...aod's could be ordered w/ 3.27's if you have 3.27's you will see about 2 tenths MAX
but if you have 2.73's then maybe closer to 1/2 second
my first 5.0 was like that,(3.27's) i swapped to 3.73's and hardly noticed a difference same et's and mph pretty much
ax code on the door tag is m=2.73
z=3.08
e=3.27
i would go 4.10 for sure in an aod
my old notch t5 w/ 4.10's was running out of gear but running 12.50's on 75 shot and stock motor, 13.20's on stock motor NA
shift lite w/ 5800 chip was lighting up right as i went through the traps so i had a couple hundred rpm to play w/ and like said b4...you can bump up to a larger tire a lot cheaper than swapping a gearset out cuz it ain't unuff.
that stroker or 351 will have more rpm left than it knows what to do with w/ 4.10's....don't be scared of it.
although my new car i am only going 3.73's
i still say 4.10's are the best.
i'm not doing a dedicated drag suspension, i'm keeping my car streetable so thats why i'm going 3.73 , keeping it multi-purpose
I have this same problem,iv been thinking and my dads been telling me the ups and down of 4:10's,and I think im gonna go this the 3:90's.I'm also running 27' tires also, but all and all 3:90's are the safest gear and i do think you'll be wishing for 4:10's. And on the other thing.....B&M shift kits are garbage.The BEST shift kit for a AOD is a Bauman shift kit.I have one and could not ask for more in the shift quality and not a bad price...$59.95 here the site to go look it already on the right page and all just scroll down.I also recomend getting the pressure valve,its about 40 more bucks but if its a high milage tranny its worth it