1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

72 fj40 turning 35's or 33's

Discussion in '40- & 55-Series Tech' started by Cruiserhead05, Jun 30, 2003.

  1. Cruiserhead05

    Cruiserhead05 SILVER Star

    Messages:
    3,465
    Likes Received:
    10
    Joined:
    Jun 25, 2003
    Location:
    Marshall, VA
    I have friend fixing up a 72 gj40 real nicely. Onyl thing it will need is a lift. I would love 35's but i want to know how that stock F engine will do with those. i had a 72 early with 31's. What will highway speeds be with 35's and 33's. i know i'd do a 4 inch lift but what would be better 35's or 33's???
     
  2. Cruiserhead05

    Cruiserhead05 SILVER Star

    Messages:
    3,465
    Likes Received:
    10
    Joined:
    Jun 25, 2003
    Location:
    Marshall, VA
    Correct its a 72 FJ40 not gj40. my typing skills are in some serious need of help.
     
  3. rusmannx

    rusmannx

    Messages:
    1,159
    Likes Received:
    13
    Joined:
    Feb 9, 2002
    Location:
    HIT IT!
    i have the same modle/year with a four inch skyjacker and it pushes the 33's no sweat. i wouldn't hesitate to go with 35's (i wish i would have), and if you get there and don't like the performance it will give you a nice excuse to throw in soume 4.56's
     
  4. CruisinGA

    CruisinGA

    Messages:
    6,163
    Likes Received:
    8
    Joined:
    Mar 27, 2003
    Location:
    Georgia Tech
    Can always drop in a granny tranny such as SM420 to give you a low enough first gear for 35's, and retain your 4.10's for better highway. The stock 4.10 should be fine for the 33's. A lawn mower engine could push 44's if you wanted it to. All that matters is gearing for trail running. Its mudding where you need horsepower.
     
  5. LC_Hamma

    LC_Hamma The Anti-Leafer

    Messages:
    2,660
    Likes Received:
    6
    Joined:
    Nov 11, 2002
    Location:
    Dallas, Georgia
    A "stock" F turnin' 33's or 35's won't be very happy because of the "stock" 3 speed tranny gearing. You'll be smokin' your clutch on the trail. As mentined above, an SM420 swap will cure that problem. Even on the road, you'll be smellin' clutch smoke leaving stop signs. BTDT!
     
  6. Landpimp

    Landpimp GOLD Star

    Messages:
    14,687
    Likes Received:
    869
    Joined:
    Mar 14, 2003
    Location:
    PNW

    I agree the 3 speed 1st gear has trouble with 35's even around town. Everything else is fine, just 1st gear isn't low enough. The motor will be fine, 4.11 are fine.

    John H
     
  7. Cruiserhead05

    Cruiserhead05 SILVER Star

    Messages:
    3,465
    Likes Received:
    10
    Joined:
    Jun 25, 2003
    Location:
    Marshall, VA
    Ok, 35's may be a little much for the 3-speed. 33's will be fine though wont they, i have now an 82 w/ 33's and its fine. 3.70 gears kinda suck off-road but i dont smell burning clutch.
     
  8. CruisinGA

    CruisinGA

    Messages:
    6,163
    Likes Received:
    8
    Joined:
    Mar 27, 2003
    Location:
    Georgia Tech
    I will be running 33's with the 3 spd temporarily for no more than a month while I get my SM420 conversion together. Then I will be much better off than before, little better on the highway with 33's and much better around town and offroad with a 7:1 first. :D