I got talked out of 3.73's a few years back by a local mustang shop. The guy said just about all the street stangs around ran 3.55's. so I went with them (although I went there for 3.73's but got talked out of it ).
Ran the 55's for about 6 months or so and with a fairly mild 302 at the time, they felt OK but not that big of a deal over the 3.08's. It deff felt like it could of used more gear. mileage was decent, but due to installer error, the gears started to howl. long story short, got the entire rear guts replaced free of charge and this time had 3.73's put in. mileage picked up by 2mpg city & 3-4mpg freeway and just a far more fun & enjoyable car to drive.
IMO, for the approx 150 rpm diff between the 2 sizes in 5th at 70 mph, 3.73's are are a far better all around gear for a mild-moderate 302-306. I just wish they made the 3.90's back then With the 347 I have now, the 73's make very nice use of the TQ this motors makes and wouldn't want any other gear size for the street. They feel great even when N20 is used.
Just my $.02
Scott
Ran the 55's for about 6 months or so and with a fairly mild 302 at the time, they felt OK but not that big of a deal over the 3.08's. It deff felt like it could of used more gear. mileage was decent, but due to installer error, the gears started to howl. long story short, got the entire rear guts replaced free of charge and this time had 3.73's put in. mileage picked up by 2mpg city & 3-4mpg freeway and just a far more fun & enjoyable car to drive.
IMO, for the approx 150 rpm diff between the 2 sizes in 5th at 70 mph, 3.73's are are a far better all around gear for a mild-moderate 302-306. I just wish they made the 3.90's back then With the 347 I have now, the 73's make very nice use of the TQ this motors makes and wouldn't want any other gear size for the street. They feel great even when N20 is used.
Just my $.02
Scott