Ok time has come to put a new diff in the clubby... But I�m stuck as to which gears to chose. 3.45, 3.7, or 3.89. Its a Series 1 VT with the 197kw 5.0ltr in it. Pretty much stock expect for exhaust, trans with a 2 grand stall, k&n filter etc. I will be doing a cam and a bit of head work in a few months but for now I just want to do the diff. I do a bit of highway driving (maybe 20min or so every couple days.) but besides that it�s pretty much just city driving. Currently i get around 500kms - 550kms out of a tank which I am quite happy with do don�t really want to lose heaps of fuel economy but I no I will. So what would you guys recommend going 3.45's, 3.7's or 3,89's? Any help would be great. Cheers

You should already have 3.45s? I'd go for 3.9s or 4.11s to get a VT S1 going. They're too heavy for that sort of power

I thought they came out standard 3.08's.

Id go 3.9. A mate ages ago went 3.45's and we told him he'd regret it. He later changed to 3.9's and was happy as larry.

If you're not doing much freeway driving get 4.11s.

3.7 or 3.9s are the go.

yea i am thinking 3.9's is the way to go. Is there seriously much difference between 3.7 and 3.9's?

Quote: Originally Posted by lt2009 [View Post] yea i am thinking 3.9's is the way to go. Is there seriously much difference between 3.7 and 3.9's? Not really maybe 100-150RPM depending on what size wheels/tyres you have.

Go 3.9's..I just changed mine from 3.07 in my clubby and it feels like a different car

3.9s are the way to go for an auto mate had them in my ss went realy well