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epfatboy · 04-14-2018, 07:13 PM

Yeah sorry about that.

Tranny is a 4L80E, the current tire is a 315/35R20 so its just a little over 28.5" tall.

Not worried about the pinion, it's the axles that let go first and honestly with a street tire I don't how I'd twist a 30 spline axle.

Seems like I should stick with the 3.73 and see what happens given the lack of difference in RPM. I know most of the turbo guys like a 3.42 but I'll give this a try and see how I like it. Plus keeping the gears will make adding the posi unit a lot easier.

04-14-2018, 07:13 PM	#4
epfatboy Registered User Join Date: Mar 2018 Location: Barrington nh Posts: 101	Re: 12 bolt truck rear. Yeah sorry about that. Tranny is a 4L80E, the current tire is a 315/35R20 so its just a little over 28.5" tall. Not worried about the pinion, it's the axles that let go first and honestly with a street tire I don't how I'd twist a 30 spline axle. Seems like I should stick with the 3.73 and see what happens given the lack of difference in RPM. I know most of the turbo guys like a 3.42 but I'll give this a try and see how I like it. Plus keeping the gears will make adding the posi unit a lot easier.