3.7 diff and bigger tires - void driveline warranty? improve acceleration?

[talljoe]

Looking for a bit more 'break neck' acceleration, but I'd like to keep my warranty. I'll be going for a walkinshaw power pack soon but I'm also considering tire/diff upgrades. A few qs...

Will a 3.7 diff -

Improve acceleration in first?

Void my driveline warranty?


Will wider tires on the rear -

Improve traction (& therefore acceleration) in first? (or when it may otherwise wheelspin)

Void my driveline warranty? (you can effectively apply more force to the whole driveline, albeit slight)

What's the largest / grippiest I can fit, realistically? Thinking about 305s :P Not sure on legality of some of them, especially drag style tires, though you can get them somewhat 'modified' to be legal?

[walesy]

yes a 3.7 ratio will improve acceleration greatly in all gears, i know VE's can fit 275 piece of piss so maybe 305 will fit, unsure of the warranty side of things you would be best to talk to the dealer you bought the car from just to be sure

[TinSnips]

The W427 used a 3.7 diff from memory, so holden should be able to supply you with one - if you get them to supply and fit, then warranty should be fine - won't be cheap though. Done outside of a holden dealership, I'd say your driveline warranty would be kaput.