ok i know i have a gm 10 bolt but what width is my rear end is it8.50 8.20 or 7.5 i am looking at puting 342 gears and possibly a 373 in my rear and i need to know exactly what rear end i have thanks

 

Thirdgen car's come with a 7.5 inch rear end. so if you look in jeg's you would get gears for 82 to 2002 camaro

 

thanks

 

allway's glad to help

 

oh yea and i wanted to ask how bad will the 373 kill my gas mileage i have a 700r4 with overdrive

 

it shouldent be that bad cause we have overdrive. but if your like me and use your car at the dragstrip and drive it on the streat i would ge 3:42's That's what im getting here pretty soon

 

thats what a couple people i know have said thanks again

 

im running 3.42's and so far that combo is working good.

 

If you want to see what the gear ratio change will due to your cruise rpm check this out http://www.f-body.org/gears/

 

between 3.42 and 3.73 it is only a change of about 200rpm at 65mph. that will change yoru mileage at all. actually, gears in general seem to have very little effect on mileage from what i have seen. i went from stock 2.73's to 3.54's and kept teh same mileage. blackbird305 went from 2.73's to 3.73's and lost like a half a mpg on average.
3.73's are really teh best all around gear for the auto. good highway cruise and great track gains. 4.10's are really teh best gear for an auto at teh track, but then you get to see your cruise rpm up around 2600-2700 on the highway, that freaks a lot fo people out.

later
tim

 

Actually for our cars a 4.56 would be better at the track. Heavy car <3 low gears. I wouldn't go lower that a 3.73 though. 3.42 or 3.73s (I like the 3.73s)

 

weight aside, on a internally stock LO3 motor ... a 4.56 gear ratio would be a bit too much to compensate for the stock powerband

 

look at my engine setup in my sig. i get 10 city 16 highway

 

3.23 and 23 mpg avg, 28 pure highway. 12-16 city or lead foot lol.

Mileage depends on how you drive.

I've also tweaked around my air intake so I have ram air and my throttle response is changed so dramatically that I can hold 85 mph with 1/8 throttle. Very rarely do I reach 1/2 thottle on my car on my daily driving.

With my 15's on right now, I can spin my open side at 1/2 throttle, and spin both tires at 3/4 throttle.

It's kinda weird having the driver's side spin on you.