2:91 or 3:55?

That sounds like a happy build combination, that’s a very slick looking car! With the .69:1 overdrive and lockup, 3.55s, no question. That’s equivalent to 2.45s in overdrive, which will have you 2000 rpm at 60 and at 2600 rpm cruise (right were the torque is starting to really happen) at 80 accounting for tire growth at that speed. Happy Motoring! The 2.74:1 low will probably be a challenge for traction, but the 1.54 second will give enough rpm drop to help recover and get things rolling.