5 Speed gearbox or a Lower Ratio Diff??

[Cyclamin]

Hi,
Pretty sure my WB has the 3.08 diff , revs at about 3,000 and does 120kph. I've heard of people putting in 2.78 diffs , but then the 253 is not good for towing. Would it be better to find a 5 speed for it and if so what are the options??
Obviously heard of the Celica/Supra gearboxes but are they strong enough??
Any Thoughts??
Cheers

[Valencia]

would be a cheaper option to change the diff ratio to 2.78 should be ok still to tow
gearbox conversion will cost quite a bit and the supra box is way strong for a 253

[HK1837]

I'd change it to a trimatic and 2.6:1 diff. Celica and Supra boxes are OK behind a 253 but you will still bust them towing. If you want to tow use an auto, nothing better. Just use good fluid and a big cooler. You may have a 3.36 too, just depends upon tyre size.

[Cyclamin]

Thanks , have to say i love the manual and would not like to go to an auto. (My daily drivers are autos). Did not consider the tyres though. It has the GTS rims and tyres look fairly standard , could you put a bigger rim and tyre on it (keeping the profile the same) or am i really starting to stuff it up , guessing i would/should change the front wheels/tyres as well.

[adam perth]

don't run a 253 with a 2.78. it will die every time you hit a small incline on the open road at 100 km/h.

[buck]

I have a wb 253 with 3.08 diff ratio, its is doing 2600 rpm at 100klm, i think you have got a 3.55 diff which my old hz had and it was around 3000rpm at 100klm.
3.08 is perfect for 253.
my mate has a 5 speed supra with 253 and 3.08 diff , 2000rpm @ 100klm fine for hills dont have to change down, just depends what your 253 is like, mine could easily handle a 2.78 diff, as it around the 140-150 kw mark.

[Vombil]

ive got a 308 with supra 5 speed and 3.55 diff. 5th gear is heaven. If you want to stick with manual and tow whilst still having the ability to hit the highway, i think the 5-speed is the way to go. Tall diffs are shocking for towing. My bro has blown 2 aussie 4speeds in two weeks towing a small boat with a 2.78 diff. Never had a problem until he changed diff ratios. he went 3.55 to 2.78. Even without a boat on the back he had trouble taking off in 1st with the 2.78!

Id agree with the others above with regards to ratio, 3.08 would probably be the best all rounder. maybe a 3.36 with a supra 5 speed in your case

let us know what transpires

[HK1837]

Towing = auto. Manuals are a PINA for a tow vehicle. Vombil is right, you don't want an aussie 4spd with a 2.78 unless it is maybe an M22 but even then you'll hate it.

For a couple of real world manual examples:
I used to have a HJ sedan with a near stock 202, Supra 5spd and 3.55:1 diff. Running 225/65/14 tyres on the rear. It was fine, and I towed a HK KIngswood on a heavy trailer from Newcastle to Tamworth with this car. With a 253 you'll push a 3.36:1 no worries. I also had an LX hatchback with a worked 202, Celica 5spd and 3.08:1 diff running 245/60/14 rears. It was fine as well, used to tow my ski boat with it up ramps etc. It had a 3.25:1 1st gear from memory. Supra in the HJ was a W55 Supra I think.