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cparman · 10-20-2009, 07:48 AM

I went to a site that has an RPM calculator, and here is what I did
255/70r15 tire is 29" tall
3.08 gear
.67 OD
should run 1500 at 65 mph.
Now with that said, I would like that number on the highway. BUT, around town you might need to run it in 3rd gear. 3.42 would be my choice for a rear end gear. I have the above with a 3.73 in my truck, and FOR ME it seems the rpms are a bit high at 65-70. My trans is a 700r4

10-20-2009, 07:48 AM	#9
cparman sharp as a marble Join Date: Jan 2007 Location: atlantic beach,florida Posts: 1,082	Re: 2004R trans with 3.08 axle I went to a site that has an RPM calculator, and here is what I did 255/70r15 tire is 29" tall 3.08 gear .67 OD should run 1500 at 65 mph. Now with that said, I would like that number on the highway. BUT, around town you might need to run it in 3rd gear. 3.42 would be my choice for a rear end gear. I have the above with a 3.73 in my truck, and FOR ME it seems the rpms are a bit high at 65-70. My trans is a 700r4