Don't know if this is a general rule, but in '72 I believe the 307 engine came with 3:73. My '72 (bought new by my father) had a 350, three speed manual and a 3:08 rear end. Great interstate cruiser and good gas mileage - the 350 had gobs of torque. A little hard on the clutch when starting with a trailer behind, though.

---> Bill