[jaykebab]

Hey guys doing an ls1 conversion from a 2.8 Gu just wondering what gearbox would be best? And in terms of ratios? 4.2 , 4.5 or 4.8 box?
And does anyone know where I can find lists of ratios for all the box's??
And if Any one is after a 2.8 gearbox the one I'm ripping out is a not long ago reco.

 

[BoostinMav]

Throw a Nissan auto behind it with a decent valvebody

 

[jaykebab]

Naaaaaaar, had an auto once before, never again!

 

[guitarist]

you will have 4.6 ratio's in the diff, so it depends on what tires you are going to run, if you have 31's with 4.6's and a 4.2 box it will revving its tits off and you will be doing 60pkh.

 

[jaykebab]

with 35's on the std 2.8 gearbox with 4.6's it sits on about 2000rpm, im confused with what your saying about the 4.2 box, is the final drive ratio a lot lower in the 4.2 box than the 2.8 box? i assumed 5th gear would be similar if not the same on the 2.8 , 3.0 , 4.2 , 4.5 , 4.8 .
im wondering what would have the best ratios in terms of matching the torque

 

[BIG_BOY]

GQ 4.2 petrol manual 1st 4.556:1 diffs 4.11:1

GQ ST 2.8 turbo diesel manual 1st 4.061:1 diffs 4.625:1

GQ ST/GU 4.2 diesel manual 1st 4.262:1 diffs 3.9:1

GQ (not ST) diesel manual 1st 4.55:1 diffs 4.11:1 (most commen)

GU 4.2 turbo diesel manual 1st 4.262:1 diffs 4.11:1

GU 3.0 turbo diesel manual 1st 4.262:1 diffs 4.375:1

GU 4.8 petrol manual 1st 4.085:1 diffs 4.375:1

also have

NISSAN GQ 5-SPD 1st-4.55:1 2nd-2.62:1 3rd -1.52:1 top/4th-1:1 OD/5th-0.83:1 rev 4.24:1

Nissan 5th GU 4.5ltr OD=0.91:1

just a few numbers i found when thinking gear boxes for my rig.