Rearend ?

[MustangCowboy]

What rearend to the 4cyl cars have? I Know 5.0's have an 8.8 but was thinking the 4 bangers have like a 7.5. Is this correct? Will the 8.8 go into my 4 banger with out major problems? Does anybody know what gears a 91 4cyl auto would have? The reason I am asking is because I can get an 8.8 with 3.27 posi, and I would love to improve my off the line but I dont know what I have now, and I was wondering how much this would kill my highway.

[fitz101]

you should be good with the 8.8 and the 3.27 gears, gas mileage shouldnt be bad with that gearing. And, I believe you are right with the 7.5 rear end off of the 4 cylinder. I also believe the 8.8 should go in pretty easy, not 100% sure on that though.

[NoMo5o]

Four cylinders come with 7.5. They are usually geared lower than 8.8's probably 3.27's or 3.42? So an 8.8 with 3.27's shoudn't effect your gas mileage. If the 8.8 is from a mustang it will bolt right in with no modifications.

[Project$200]

Originally Posted by NoMo5o

Four cylinders come with 7.5. They are usually geared lower than 8.8's probably 3.27's or 3.42? So an 8.8 with 3.27's shoudn't effect your gas mileage. If the 8.8 is from a mustang it will bolt right in with no modifications.

Is the e-brake cable not different from the 5.0 cars to the 2.3?

[rockytoohot]

I believe the e-brake cables are the same and the 8.8 will bolt right in with no modifications needed.

[MustangCowboy]

thanks that is what I was hoping to hear. I need to do a vin check to see what gears I have, since there isn't a little tag on the rearend.

[MustangCowboy]

I just went and looked at the door tag and I've got 3.73's now, so I deffinitely don't want 3.27's. I am willing to sacafice some top end to get some off the line, so what will going to 4.10 or 4.11, or whichever it is in the 8.8, do to my top end.

[BLUE92]

That small of a change in gear ratio will not effect your top end too bad, but on the same note it won't effect your bottom end a whole lot, but it is still a small improvement, so i say go for the 4.10s.

[mr deeds]

Hey cowboy,

4.10 = 8.8 inch
4.11 = 9 inch

Gear ratios are always subject to debate. With the smaller displacement engines, some say 3.73 w a manual and 4.10 w an auto. It's all subjective, and depends on how you drive and what you are looking to do. With your HP and desire to pull better off the line, I'd go with the 4.10s. I had 4.10s in a V6 and loved them. Which to get depends on how you drive. You'll notice the difference in the pull in the lower gears, but you shouldn't notice a HUGE difference between what you have now. At interstate speeds the 4.10s will rev a little higher than the 3.73, but nothing to be concerned about. More important, whatever rear gears you get, be sure to get a limited slip posi. That will make more of a difference in performance than the difference between 3.73 and 4.10. BTW, if you decide to swap the axle, be aware when shopping that the pre-1999 solid axles are about 1.5 inches shorter than the 99-04 models.

[MustangCowboy]

Thanks that really helps. If anyone has a fox body rear with 4.10 or something higher than 3.73 that they want to get rid of let me know. Every little bit will help and I was planning on swaping the gears when I do the turbo anyway.