Quote:
the thing is i dont know what the gearing is in here know all i know is its a 10 bolt without posi, so with what gear is in here now i havent a clue, the car at the moment is a mild 350, im looking to push it to a nice streetable 400hp/400 lb/ft with a bit of gas
so would like a nice set of gearing or traction shall i say!!!
Finding the Gear Ratio with the Rear Differential in the Vehicle
1. Park your vehicle on a level, paved surface and chock the front of the front wheels.
2. Insert a floor jack under the center of the rear differential and lift the rear wheels off the ground.
3. Position two jack stands under the rear axle tubes, one under each side near the wheels. Place two more wheel chocks behind each front wheel to prevent the vehicle from rolling.
4. Clean an area on the driveshaft with a wire brush. This area should be a 1-inch thick band that goes all the way around the driveshaft tube near the rear yoke.
5. Insert a degree tape into the cleaned area of the driveshaft.
6. Tape a stiff piece of wire to a full soda can to use as a pointer. Bend the wire as needed and place the pointer at a start line on the degree tape. This start line can be any line on the tape. Monitor the start line to determine exactly how many full and partial rotations the driveshaft makes in one complete rotation of the rear wheel.
7. Tape a pencil to the rear quarter panel so it hangs straight down towards the center of the rear wheel as a pointer. Mark a corresponding line on the sidewall of the tire at the pointer with a grease pencil. Do not rotate the wheel while doing this.
8. Shift the vehicle into neutral so that the driveshaft can be rotated.
9. Turn the driveshaft slowly while counting the full rotations that the driveshaft completes as well as the number of gradation lines of the degree tape that pass the wire pointer for a partial turn. Stop rotating the driveshaft when the rear wheel rotates exactly one full turn, mark to mark.
10. Multiply the full turns of the driveshaft by 360 degrees and the number of gradation lines that pass the pointer on a partial turn by 22.5. Add these two numbers together and divide the answer by 360. This is the rear end gear ratio. For example: Four driveshaft rotations equal 1,440 degrees, and three grad lines will equal 67.5 degrees. Add these together to get 1507.5 degrees. Divide 1507.5 by 360 and the answer is 4.1875. Round it and you get a ratio of 4:19.