Converting dual range 4WD L-series from 3.7 to 3.9

subalex · Post by **subalex** » Mon Feb 27, 2006 10:47 pm

I've just brought home an '85 model L-series that is only high range 4WD through the push button on the gearshift. This operates on the 3.9 diff ratio. However, my project car is a '91 model, has 3.7 diff's in it and it's a dual range gearbox.

While both are manual cars I wondered if it was possible to change the dual range to 3.9 easily using some of the older car's gearbox parts? Is the fact that one is single range and the other is dual range going to be a problem?

BaronVonChickenPants · Post by **BaronVonChickenPants** » Mon Feb 27, 2006 10:55 pm

Yes it is possible but I don't think it'd really be worth it, others may differ, but ur only looking at about 200 rpm difference at the same speed, bout the same as going from a tyre profile of 75 to 70 or vice versa.

Jordan.

MUDRAT · Post by **MUDRAT** » Tue Feb 28, 2006 3:33 am

Yeah, there ain't a big difference between the two, even in low range.

You're lucky too because 3.7:1 rear LSDs are plenitiful and relatively cheap.

subalex · Post by **subalex** » Tue Feb 28, 2006 2:27 pm

That's what I thought. Not worth the effort. As for LSD's (no not the drug) is what I'm after long term too. I'll just fix the engine and other worn parts first.