i have an 88 trans am 350 tpi...700r4 tranny....how can i tell if i have a 2.77 or 3.27 rear end???? thanks

 

You'll either need the RPO code or you can get the axle code off the front of the passenger side axle tube.

In 1988 the 350 TPI cars with the 700R4 had 2.77 as the standard gearing and 3.27 was an option.

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87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

You can also get a good idea by putting the rear of the car on jackstands, marking a spot on the driveshaft, turning the tire, and counting how many times the driveshaft rotates. It's not exact, but it'll tell you if it's 2.77 or 3.27.

 

just simple math.....
note your rpm in OD with TC locked at say 60 mph.
rpm / gear ratio / 336 x tire diameter = mph

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86 T/A 5.0
?????
93 Civic 1.6L
13.5 @ 100 mph