Excellent news on the confidence factor! My last alignment guy said 9 degrees caster is a majac number.
Thinking you do need a tach so the ear doesn’t play tricks, Blue has a noisy direct style fan that makes you feel like it’s twisting to the moon but in reality, it’s just a noisy direct fan. Big changes, you’d think with 3.07’s it’d be a freeway flyer but 4.10’s and OD would be a really sweet combo best of both worlds.