To make it short and sweet: 2.5 to 4.0 swap is generally more money for such small returns. If you're gonna swap, go V8 - you'll find great support for it online. But that means you'll also be upgrading transmission, t-case, axles, driveshafts, wiring harness, engine mounts, radiator, etc.
35's on a D30 and D35 setup will set you up for failure if you wheel it. You'll want 5.13 gearing, which isn't available on the D35 (that I'm aware of). I run 33's and 4.88's and have upgraded my D35 to 30 spline alloy shafts and ARB.
You'll also need to swap the transfer case as I believe the inputs from the transmission are a different spline count.