I would use either of the 2.87 gear trannies because they have a numerically lower first gear, so it is actually usable because you can go faster than 6 mph before you have to shift. A 3.27 or or numerically higher first gear is good for steep hill climbing or a lame V8 or even lamer 6 cylinder engine.
T5 Z SPEC . . . . 2.95, 1.94, 1.34, 1.00, 0.63
TKX . . . . . . . . . .2.87, 1.89, 1.28, 1.00, .068