Pro gear life

Originally Posted by Dana Fitzpatrick

I have a 3300lb,9 inch tire 68 Camaro,4-speed, that I shift w/o the clutch.Runs mid to high 9's. It has a complete Strange 12-bolt,spool,pro gears, support cover.I'm looking for estimates on gear life and what to look for when I pull the cover off.As always,thank you.

What gear ratio? Big or small block? I ran 4.88's they lasted around 75 runs with the stick. When I pulled the cover, the teeth started developing cracks on the ring gear. 3400 pound car leaving around 5k. Running 10.60's