top end

[greg]

1. will a 60 rear axle swap into 74-40,1f 3spdtrans and transfer for a higher top end for street ,if not what options do i have? 2.will i notice the difference if i go from 31 to 33s top end ? thanks in advance the knowledge on this site is top shelf.

 

[66fj40x2]

Greg, to swap the axle you would need to relocate the spring perches and swap a 3.73 gear into the front as well. I think the diffs will swap between the 40 and 60 but can't recall if a '74 is fine or course spline. You have to swap out the side gears in the diff too. The taller the tire the more top end.

 

[PabloCruise]

Taller tires are a cheap way to overdrive it = lower RPM for same speed

I think the diffs went fine spline in '78

 

[76BigheadFJ40]

the difference will not be much, when you go bigger tires, but it is the cheapest option

 

[largenfirm]

the difference will not be much, when you go bigger tires, but it is the cheapest option

I went from 27 inch tires to 33 inch tires, and my speedo is off by 5 mph at 25mph, and off by 10 mph at 55 mph.

IOW, when the speedo says I'm doing 20, I'm going 25, and when it says 40, I'm going 50!

Confirmed with a GPS.

One of these days, I'll take her down to a speedo shop, and have a ratio box installed.

Kirk

 

[65swb45]

The 60 pumpkins are a direct swap for you OTHER than the fact that the flanges are different, coarse to fine. If your present pumpkins are newer than 1/74, and your donors older than 4/85, the flanges should have the same pattern tho.

I always tell customers that ask me this question that the very best thing they can do is find a buddy that already has the tire size you're interested in and ask to 'borrow' them for a day so you can test them out for little more than your elbow grease to swap them [and whatever liquid lubricant you ply your 'friend' with. For a fair comparison, you would want to test a tire 10 percent larger than what you have [equal to the difference in gear ratios, and not any wider than what you have, so you are not throwing excessive drag into the equation.

 

[Poser]

You have to swap out the side gears in the diff too.

This IS NOT ACCURATE.



Coarse spline side gears in the differential were ran until the 1968 model year Land Cruiser, when they switched to the fine spline. Any Land Cruiser from 1968 and on will have fine spline SIDE GEARS in the differential.







Good luck!


-Steve

 

[greg]

been asking everybody for the borrowed 33 experiment no luck yet ,i dont think im going to notice a difference from 31s to 33s its worth a try for sure . you have to drive on alot of pavement to get to the dirt around here, im not really lookin for more top end speed just a little more driving comfort on the hwy,seems like the engine just has to rev to high and is beggin for higher gear to be shifted, thanks for all the input , and update info on the fine spline .is a axle swap best way to deal with this.? thanks again

 

[surfpig]

I always tell customers that ask me this question that the very best thing they can do is find a buddy that already has the tire size you're interested in and ask to 'borrow' them for a day so you can test them out for little more than your elbow grease to swap them [and whatever liquid lubricant you ply your 'friend' with.

That's what I did, with a six pack of Anchor Liberty Ale and a balance job on the tires I road-tested 33's on my piggie (thanks, Greg). for a day or two to get a feel for the difference: flat land, the motor just chugs along happy as can be, 70 mph or so. Hills, not so great, but hey, it's a brick on wheels, what do you expect? Offroad, I think you lose a little for crawl ratio, but not enough for me to worry about with what I do, and the clearance is a big plus. As for driving comfort alone, I'd say DO IT! One of the single best things I've done: ride is better, engine isn't whining anymore, I can hear my stereo (sorta) better. ( and a 55 just begs for taller tires... ) According to GPS my overdrive is 16(.666)% over stock, that sounds about right with other accounts here...

My Bigfoot's callin' my name...

Nial