[PontiacMatt72]

After developing a noise in my 70 GTO M20 transmission, I discovered a broken gear tooth on first gear. Time to upgrade to a TKX (been wanting to for a few years now)

Car currently equipped with a 10-bolt with 2.93 gear. Have a 12 bolt rear ready to build.

I’m trying to decide whether to purchase the close ratio TKX (2.87 first, .68 fifth) or the wide ratio (3.27 first, .72 fifth).

If I go with the close ratio, I’d likely build the 12 bolt with a 3.55 or 3.73 gear. If I go with the wide ratio, I’d likely go with a 3.08 gear for the 12 bolt.

Car has a ”stock-spec” 400 (2802 cam, everything else 1970-correct). It’s a cruiser, not a race car. Might play around with some occasional autocross events, but it’s 98% street-driven cruise-in car.

So, wide ratio with 3.08 or 3.36 rear gear, or close ratio with 3.55 or 3.73 rear gear?