70mph what rpm
#1
#4
Gear vendor lucky!!! I don't have the room for one
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Reason I'm asking is cause I got 37" tires 4.10 and at 60mph I'm doing 2000 rpm and I don't want to hurt my motor but I would like to go 70
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Reason I'm asking is cause I got 37" tires 4.10 and at 60mph I'm doing 2000 rpm and I don't want to hurt my motor but I would like to go 70
Last edited by cumminsblazer; 08-12-2011 at 12:42 PM. Reason: Automerged Doublepost
#5
They weren't meant for speed to begin with...I keep mine at 65mph for the most part on interstates and such
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but if you can find a cheap 3.55 rearend then go for it just make sure you get one for the front end too if its 4x4
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but if you can find a cheap 3.55 rearend then go for it just make sure you get one for the front end too if its 4x4
Last edited by Glantz496; 08-12-2011 at 12:45 PM. Reason: Automerged Doublepost
#7
Is that correct? The reason I ask is because the ratio/rpm calculators out there always put my motor at 2000 RPMs at 60 MPH with 235/85R/16 tires with 4.10 gearing in 5th with G360 trans? With 37" tires and 4.10s I would think you would be at a lower RPM than 2000 unless your gearing has been changed to lower than 4.10
#9
Yeah, something don't sound right. I'd think an OD trans much more than 1-1 in top gear would get the final drive rpm down better than that with 37" tires.
#10
when i did my swap the truck had 4.10 gears with the a518 and yes about 60 mph it is about 2000 rpms is right, for pullin my 5th wheel it was nice. but daily driver it sucked, i put in some 3.73s now its about 1800 @ 70 mph,not so good for pullin but OK. i then tried 3.54s, it will flat haul *** but pullin sucked, (if you don't plan on pullin anything then i would go with them. to get the 3.54s in the back i put in a Dana 60 (14bolt does not have 3.54 option ) I went back to the 3.73s for all around use. 60 mph is about 1600 rpms in O/D hope this jiberish makes sense