it says its a 4+3 overdrive??
Never heard of it. Try posting in a Corvette Enthusiast forum to see if they know. Here is one: http://corvette-nation.com/corvette-forums/viewforum.php?f=10&sid=a113a284cd5ecea2c957e535d0e6ceb3
The car has 2 trannys 4 speed and a 3 speed automatic. Theres 1st gear 2nd gear 2nd gear od when button is engadged 3rd gear 3rd od 4th then 4th od thus giving you 7 gears 4+3 overdrive
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