supersick99z

iTrader: (66)

When I bought the car the guy SAID he and a buddy had 4:10's put in at some point when he owned it at a shop. Shop had no record of his name in the system, but that's not to say it wasn't done under another name (like his dad's).

Any simple way to tell if that's what's really in it?

Thanks in advance fellas!

fastassls1maro

iTrader: (22)

might be able to tell by rpms/mph if he had the speed recalibrated.
i think mine was somewhere around 60mph at like 2k RPM with my 4.10 gears
someone can chime in if that is incorrect.

hevymetalg

iTrader: (1)

Pop the rear cover off the diff and look on the ring for the numbers divide the first number into the second number.

TImmy_Jones

iTrader: (4)

Dont pop the cover on anything. Get a GPS and check your speed against your RPMs. Stock gears are like 2K @80MPH the 4.10s will be much higher.

*I say GPS because it eliminates the possibility they were installed and never had the speedo corrected.

VandykeT/A

If its a M6 I think stock is 90 at 2k. 410s on the stock height tires will be about 74-75 at 2k in 6th gear.

supersick99z

iTrader: (66)

Based on what y'all are saying about speed vs rpms it's definitely got 4:10's! I turn like 1800-2000 at like 60-65 mph

Franchi

Using the GPS is how I checked mine. Found I had 3:55's in, and went to 4:10 gears.

supersick99z

iTrader: (66)

My gps and speedo are with 2 of each other so I would assume he had it recalibrated. He had it done at Tick Performane here locally

99FormulaM6

iTrader: (21)

http://www.f-body.org/gears/

Fill out the info on the left and it will tell you what your speed should be based off RPM and what gear you are in.

supersick99z

iTrader: (66)

Actually noticed this morning about 68-70mph=2k rpms, but according to the chart I filled out, many other mph and rpms match to be 4:10's?

99FormulaM6

iTrader: (21)

If you are in 5th gear, then yea, that is correct. However, next time shift into 6th and save some gas

supersick99z

iTrader: (66)

That's 6th

Catmaigne

iTrader: (6)

Or you could just jack the car up, mark a tire and the driveshaft with chalk, and rotate that ****.

99FormulaM6

iTrader: (21)

68-70mph in 6th gear would be 1800-1900 rpms if it were 4.10s in the rear. 2000 rpms in 6th gear at 68-70mph, would be closer to 4.56s same thing with what you originally said about 1800-2000 at like 60-65 mph, that is just about right for 4.56s.

VandykeT/A

google fbody gear ratio calculator and click the first one.

99FormulaM6

iTrader: (21)

I already posted that. That is whats being used to determine his ratio.

supersick99z

iTrader: (66)

I used the calculator. I'm gonna print that bitch off and have it in the car when I drive lol

99FormulaM6

iTrader: (21)

eventually you will get used to it and it will be second nature. I am not sure why the previous owner would have put 4.56s in the rear, but atleast you know.

b00geyman

i got 4:10 in my auto and at 60-70 im at about 2500 rpm

supersick99z

iTrader: (66)

Yeah he told me when he did it his decision was between 4:10's and 4:56's but went 4:10's. So hell idk I'll keep an eye on the comparison between the 2