Pinion angle help.

va-mopar said

I'm a tempting to set pinion angle on my 70 Duster. Any help/ advice would be greatly appreciated. It was a 318 with 904 trans and 7 1/4 rear. I put in a 360 and a 8 3/4 rear. It still has 904 tranny. I just took angle off tailshaft and it is. 1 degree down. What should the pinion angle be. The rear end don't have perches , so I will be weilding them on after I set the correct angle. Thanks in advance.

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If the pinion is 1 degree up, they would be parallel. Are you using any traction devices to control spring wrap? Ideally, you want the pinion a certain number of degrees lower than 1 degree up to allow for the nose of the pinion to climb upward a bit under power, and then be parallel to the transmission centerline.

The number of degrees of adjustment downward on your case depends on which type of limiter you use to control the rotation of the pinion upward under power. If you are not using a traction device, then you probably want 2 or 3 degrees nose down at rest to allow for the upward rotation under power. If you use a traction device to limit that movement, it can be as little as .5 degree lower.