Anyone Try Or Run 3.31 Rear? Thinking Bout Ditching The 3.73

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by 90lxwhite, Oct 23, 2013.

  1. If so how ya like em?
  2. Not anyone I know, but I've considered it as well.

    I'm not a fan of my 3.73's. Was considering 3.27's, but unsure if anyone has run the 3.31's and how they would correct the speedo for it.
  3. If you're n/a why the change? Mpg's? I really don't see the point other wise. Maybe 3.55's but I wouldn't go under that personally but I don't care at all about mpg. Now if it's a turbo I understand.
  4. I think all depends on how the car is to be used or driven. The 3.27's are great if you want to cruise the highway and want to cruise at high speeds...but it will take you longer to get to those speeds than if you keep the 3.73's or 3.55's. It's really a matter of acceleration vs top speed, so if you want to get to 80 mph quickly and hang there, then the 3.73's 0r 3.55's ought to be fine. I have 4.10's and cruise effortlessly at 75 mph (2500 rpms) and in 5 miles or so, the 3.27's would catch up to me. As for gas mileage....they make a Prius for that.
    A5literMan likes this.
  5. Gas mileage is not a concern.

    My car is a weekend cruiser. I don't drag race it, or speed around. I like getting on the highway without feeling like I need to always be in 5th gear. I also hate shifting to 3rd and 4th just to drive down a road with a 50 MPH speed limit.

    Just seems like for cruising around, a taller gear is preferred
  6. Mpg isn't an issue for me either. When I'm in 5th on the hwy it feels like it needs a 6th and its getting old, the engine wont settle down and cruise just keeps pulling. Kinda like driving a tractor. Also 1st gear is way too short the. The rare times I do get on it from a roll 1st redlines way to quick with no speed behind it, the cramk is spinning its azz of but im barely moving. Maybe if I was making more power the 73s would be more fun but really I wouldn't suggest em to those w moderate power as a worth while mod as so many do(that's how I ended up w em, forums...) I went from 2.73 to 3.73 so I don't see how a 3.27 or 3.31 could be any slower than when it was stock. By the way this is not a daily driver either. I can compare driving on the highway to my sisters 99 tracker she had in 99. Motor reving its a*s off to do 80.
  7. 2500 is effortlessly!?
  8. i wouldnt even think about it unless i had a snail sitting up front...
    A5literMan, HotFox and f8tlfiveo like this.
  9. I kinda get a chuckle out of the "I don't care about mileage" responses. Why wouldn't you? If you had the chance to improve mileage, without significantly hurting performance, you'd be foolish not to consider it?!? Owning a fast car doesn't automatically mean you have to have lousy mileage as well. I think the new 5.0L TiVCT has more than proven that one.

    In my case, I've got the extra "snot" of my 331 picking up the slack in the power department. I don't like the way it buzzes the tack with the 3.73's on the highway. That alone is reason enough. The better mileage accumulated is just icing on the cake.

    Unfortunately, it'll have to wait till next year. I'm up to my elbows in my wire hiding project and the weather is starting to get too cold to take on any new ones.
  10. Mileage- it's driven like twice a week maybe.
  11. .....maybe you'd drive it more often if it got better mileage? :shrug:
  12. Even if you were running a 14 some odd 1/4 w 3.73's? I don't drag race but if I was to guess I bet I'd be in that ballpark, 209 rwhp full weight. But anyway couple years ago I added 3.73s and guess what, still slow. Only now the engine is spinning like a madman while I'm going slow. In town it's ok I guess cruising at 40 in 4th but on the highway it's plain irritating. If I had a 6 spd maybe it'd be ok
  13. I swapped out the stock 3.27's in my last blown Mercury Cougar for a set of 3.73's and actually went slower. I ended up putting the 3.27's back in it.

    Going from 2.73's or 3.08's to 3.73 or 4.10's is one thing....but it's tough to really see a performance improvement either way when you start with a gear that's middle of the road like a 3.27-3.73. You will however notice the drop in mileage and additional highway RPM.
  14. 3.31's wont help a stock car in the 1/4 over a 3.73.. it will hurt it a bit. i have 4.10's now and drive it from time to time on the highway and if i had the RPM to turn the motor id run 4.30's or 4.56's

    btw what i mean by snail is a turbo. turbos like a higher gear to load them up and help spool them.
  15. And I remember switching from 2.73s. They sucked. Without me looking it up what's the rpm change @70mph going with 3.31s from 73s maybe 200-300 rpm? I only drive mine 1-2k miles a year anyway with a few strip passes along the way. I guess it's just my preference I like them and I want performance. My mpg sucks anyway because I can never keep my foot out of it.
    #15 A5literMan, Oct 23, 2013
    Last edited: Oct 23, 2013
  16. I use my 2003 GT as a reference.

    Had 3.27's, and a tall 5th gear. Crusing at 80MPH was under 2000RPM. If i downshifter to 4th gear, i was around 3000RPM at 80MPH and could roll on the gas for passing power. It felt nimble. When i wanted to cruise, i'd just toss it in 5th.

    I just loved that feeling. I thought the car was geared perfectly for a driver. I just think in my 5.0, the 373's are a bit much.

    3.31's sounds perfect to me. Just haven't heard of anyone swapping to them yet
  17. Yes I knew u meant turbo. All I'm saying for a street car the 3.73s aren't too fun, more of a hastle. More shifts to get to 60. Maybe if my car was fast the pleasure/pain ratio would be worth it but when the motor is wound way up and you're still slow, not too fun
  18. I like performance too but w mainly stock motor the 3.73s just aren't doing it. What like 20 or so mph in 1st at redline, that's good? I have stock heads w comp cam w .512 lift on in and ex w 281 duration and ported lower intake. That's all the wallop I'm packing. I guess my biggest gripe is the whaaaaaaa on the highway pulling its ass off like it needs to shift. If I was 18 maybe id like it. When I put the gears in I thought hm maybe I got something now but nope still slow I just have to shift sooner
  19. Love my 3.73's. Really woke up the car with the AOD.
  20. Don't throw out those 3.73's, within a week you will be trying to put them back in.

    With no heads the car will feel like a slug if you go down to 3.27's.
    3.55's aren't worth the work to switch from 3.73's, so your options are limited.