You're used to driving your GTO with a 2.92 rear and an M20 with a 2.52 first gear. Effective gear in first being 7.38.
Going to a 3.08 with a WR 3.27 first gives you an effective 10.07 gear. Now contemplate the 3.08 with a CR 2.87 first and you have an effective 8.84.
Either option will give you a dramatic improvement pulling away from a standing start. The difference between a .68 and a .72 final drive gear is minimal.
FWIW - you're second option in your poll is for a 3.36 rear. Not a ratio available in a 12 bolt. After 3.08, the next option available is 3.31, than 3.42 I believe.
If I were you, I'd go with the 3.08 and then decide whether you want to do an easy smoke show from a standing start (WR) or have the upshifts closer together (CR) for the occasional times you autocross and keeping the car closer to it's power band while cruising.
This is coming from someone that has run his '64 GTO with the original M20 (2.56 1st gear in '64), with the original 3.23, a 3.36 and after replacing the original 389 with a 455 with 3.42's and now a set of 3.08's (effective 1st gear is currently 7.88). I'm looking at the TKX also and think I'd be happy with the CR with my 3.08's cruising at a little over 1800 RPM at 70 MPH.
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