modie23

I'm just wondering if anyone has changed from the 3:73 gears to the 4:10 gears. I have a 05 F150 with a Hypertech Max Energy, K&n Cold Air Intake, Mass Air Flow Sensor, Ignition system, and a 50 shot of nitrous. How much more would a 4:10 gear help me get off the line and where can you purchase these at? Thanks in advance!!

luckythirteen13

going from a 3.73 to a 4.10 is a waste of time and money. the ratios are so similar youd hardly notice anything

blackbetty

what tire are you running, most likely a 4.56 is going to be best for you

wxmcpo

Honestly unless you're running a bigger tire than stock there's no need to change your gears. I'd also agree with switching to 4.10's from what you currently have isn't going to buy you much, if you're going to make the switch at least move to 4.56's. Like I said though if you're still pushing stock tires you're wasting your money.

blackbetty

i will be switching for a performance standpoint...as i have a smaller tire then stock

socaliallstar82

what are you currently running with the 50 shot? I would think that the 4.10's would actually help you off the line, maybe 4.30's if theyre available. wouldnt 4.56 keep the rpms kinda high? not too good for mpg's.

modie23

Im not worried bout gas milage. I just want something to help me get from 0-60 quicker, cause my truck is very good top end. I have stock 17 inch tires on it. everyone has told me that if i go to a 4.56 that it would kill my top end. your thoughts??

socaliallstar82

yeah, it'll fall flat on its face in the top end if you go 4.56. Im gonna disagree with every one and say you should go with the 4.10's if you want better 0-60. Do they make a shift kit for your f150's? I had one on my previous (2001) tundra and it was night and day. 4.10's, a shift kit, and a good set of headers will help. ever take your truck to the track?

luckythirteen13

everyone that is telling you your top end will dissapear is wrong. lets say your doing 100mph at 3k rpms (just a guess, not sure what the rpm would be) but when you go from 3.73 to 4.56 you would do the same mph as before but instead of doing it at 3k itll now be 3600rpm. not much of a change if you ask me. and you really shouldnt be going over 100mph on the road anyways. and if your on the track when then you will have no problems because youll be at wot and redlining it anyways.

long story short, dont listen to oppinions, do the math and get the facts. here is a formula that will help determine your crusing speed if your worried about top end and rpms

x/4.56=rpm/3.73

/ means divide.
x = new rpms after going to 4.56
so lets say you want to know how i got the 3000 to 3600 rpm change.
current rpm (3000) and mulitply it by your new gear ratio (4.56) and divide by your old ratio (3.73). this looks like 3000 x 4.56/3.73=3667

find out the top speed you want to hit on the freeway, when you get there, write down the rpm of the motor. plug that rpm into this formula and find out what your rpms would be with 4.56 gears. if the rpm is too high for you, go with a lower gear like 4.30 stick 4.30 into the formula and see where your rpms would be with that gear ratio. keep doing it till you hit an rpm you are happy with crusing at. remember, your truck is heavy, its going to take a good difference in gear ratios to feel it.
DONT FEAR THE GEAR

obusnizzle

get it tuned for nitrous with the gears.