I had a bit of a look at the gear ratios for the SLK32.

GEARS
Diff Ratio..........3.07

Gear Ratios.....Tran ratio...overall ratio...kph speed @6000rpm
1st Gear...........3.59.........11.0..........67 kph.....42 mph
2nd Gear..........2.19..........6.7..........110 kph....69 mph
3rd Gear...........1.41..........4.3.........171 kph...107 mph
4th Gear...........1.00..........3.1.........241 kph...151 mph
5th Gear...........0.83..........2.5.........291 kph...182 mph
Reverse............3.15..........9.7..........77 kph.....48 mph

TYRES
Section Width:mm........225mm
Section Width: inch.. 8.9inch
Profile ................45%
Rim Dia inches..........17inch
Rim Dia mm..............431.8mm
Sidewall Height:........101.25mm
Overall Diameter:.......634.3mm
Circumference:..........1993mm

I'm guessing the wavetrack wont change this unless you actually change the spline and pinoion gears at the same time....I currently have this opportunity - so looking for some advice/comments.

Given the torque available (and soon to be improved) from this beasty
1) should I go for a taller diff ratio if I'm eventually going to 21psi & 330rwhp?

I noted from someone already running in this area (11.7/117) that 2nd>3rd gear change is at the 4.1sec/62mph point. A 2.8 ratio'd diff may push this out to >70mph (calc 76mph on the calcs above).
2) What are the "standard" bolt-on pinion/spline ratios available - if any - or is it a special/machine job?
3) what do I sacrifice (if anything given the extra grunt from the pulley etc.)

b22b