well since i have the whole irs apart at my dads buddys shop and the diff. is sitting on a table i figured now would be a good time to replace the gears. Im leaning towards 4.10s because i plan on goin w/ a bigger blower in the near future but im torn between the 4.10s or the 3.90s. Now w/ the 4.10s i would be able to run a 28" tire and it wouldnt lower my gear ratio too much. thanks for the input
How much power you want to make??? 4:10’s are good if you plan on spinning the motor to 7K because you can keep the rpm’s up between shifts. It will also be easier on the drivetrain because the car can move easier. As far as the 28" tire do it!!! And go with a slick if you do!!! If 6K is your redline 3.73’s all day.
nooooo… no 4.10’s with a positive displacement supercharger, instant torque = no need for 4.10’s… Idk greg whats stock 3.55’s? I personally would keep those, if anything go with a 3.73… 4.10 is wayyyyy too much gear
yea i kind of got talked out of it cuz if i go w/ a bigger blower i would get no traction at all w/ the 4.10s and i dont wanna have to drive around on 28" tires all the time
as it is you spin if you nail it… if you put 4.10’s in your car now no more 140mph runs!!! 
stock gears 140mph=4th 4.10s 140mph=6th?
lol… what is your gearing in the T56, is it different from mine? I think your 1st is shorter at least (?) revving out to 6500 or so, i can take my 4th just about to 140… depending on what your goals are, that is how you should decide on a gear ratio… i mean what blower and supporting goodies are you goign with and what do these combos trap in the 1/4th? That is what you should base it on. For me, a 3.90 would probably be perfect.
i plan on goin w/ the whipple 3.4L and guys w/ stock gears and the same setup have gone 130’s in the 1/4
ugh you still want that retarded thing? Idk why anyone would want to go with somethign bigger than what is on Ken’s Cobra, even that he had to run a pulley the size of spare tire
well after next year i wanna do a built stroker motor and 25psi :burnout:
ass examinations must pay well! gotta do a fuel system and such too, its going to get priceyyy
im gona do a return style w/ the blower i figure its cheaper in the long run to go big once instead of not goin big enough and having to do it again
plus i think im gonna start sellin drugs on the side for some extra cash lol j/k
Are you going to be trying to get the best 60’s and launches the car can? Are you willing to buy new tires for track and street?
This car sees 80% street time i would say… If it were me, i would make my choice accordingly.
i do want a better 60’ but i think it would just be too costly overall to go w/ the 4.10s w/ new tires for the track and wat not i think im just gon stay wher im at
Dont you guys have AIM or something almost all these posts but 2 are between u guys lol! Keep stock gears, im sure you will be fine considering we had wheel hop at 30MPH last time in your car!
mind your own business wahoo
the advantages of having the larger blower will be that his IAT2 temps will be down a lot compared to the eaton, especially when doing back to back pulls. If you ever noticed how greg ran better times than you at the track because of a nice cold blower vs how you pulled him on the highway because he kept heatsoaking.
with the larger blower, he can do a lot of back to back pulls and the car will pull just as hard each time. i noticed this big time when i switched from the heaton to the 2.8L
also, they can make a ton of power with the proper setup/tuning.
some of the disadvantages:
-even with stock rear-end gearing, our t56 has a lot more aggressive gearing than that of fbods, you will spin like crazy with the extra added power. i can’t stab the throttle without the car breaking loose, you will always have to roll into it. unless you are running a 28" tall slick or better, i would stay with the stock gearing
-efficiency range: the large blowers don’t really hit their “good” range until you hit 24psi or better. this meaning that you will need to run a full fuel system, 100octane or better, larger maf, pretty much all the goodies. this much boost is pretty much totally overkill for the street. for example, at 16psi i have only top end power because it takes so much to spin the blower, i lose a lot in the midrange. with a smaller blower, you would have a lot more midrange power at 16psi.
however, it looks like you want to go big boost later on, so you might as well get a large blower now, but be prepared to sacrifice some midrange power unless you run 20+ psi all the time
just some food for thought. anyway, happy modding 
send a pm or give a call if you have any further questions
that is a good point about the heat soak, but for the street isnt there a lot left on the table as far as efficiency range is concerned? I guess it would boil down to what your goals and purposes are.