Rear Gears??

[69Rcode_Mach1]

Im finally starting my performance work this summer, and i wanted to know if anybody knows the ratios on my cars rear gears? It is a 1969 Mach 1 with 351 W and i don't have any tags to id ratios. I was thinking of a 3.50 posi towards the end of my work. Will the 3.50's and posi make a noticeable difference in my power?? Mileage?? Traction??

 

[65fastback2+2]

jack the rear up, put it in neutral, count how many times you have to turn the driveshaft to make the tires turn one time around.

 

[69Rcode_Mach1]

o okay thanks, i still need to some answers to my other questions lets say my car was running stock 3.23's Would i notice a big difference in the factors above.

 

[65fastback2+2]

power, u'll notice better low end take off, mpg, u'll notice prolly a 2mpg drop, and traction is based on tires also, sooooo if ur running an open 3.00 right now and go to a 3.50 lsd, u'll notice a lil improvement in traction if you have big tires, if u have doughnuts it'll just spin em easier

 

[69Rcode_Mach1]

Hey Thanks man youve been a big help.

 

[65fastback2+2]

np, once you get ur current rear gears figured out, oh and also tell us, when u turn one tire does it turn the other. then we can prolly help you get it narrowed down a lil more

 

[69Rcode_Mach1]

nah it doesn't turn the other i already did the posi test, but yeah ill have an update on the rear gears tomorrow.