Posted by Greg Coffin [4.225.208.185] on Wednesday, March 20, 2013 at 10:21:30 :
In Reply to: Gettin' ready to make PW 6X6..... posted by Doug in CO [68.177.208.50] on Monday, March 18, 2013 at 13:41:05 :
For any kind of highway use I would install 4.89s. I have them in my PW, and I have never felt the need for 5.83s when off-road with the 251. Assuming you are repowering your chassis, you will have no problems off-road with 4.89s.
If you are installing a diesel, larger tires and/or OD are just about mandatory because a diesel doesn't want to spin more than 2500rpm, and that limits you to about 55 mph with 9.00-16s and 4.89s. If you install a 4BT, you have enough room for a Ranger overdrive between the engine and SM465 tranny, or install a Spicer 3053 like Manny suggested. The track record on the NV4500 didn't hold up to the hype, sadly.
And of course, going faster means a need for better brakes, so discs on the front minimum. If you are going to haul any kind of weight on the highway, I would install discs on all axles.
And then there are engines to consider. I installed a 318 in mine because I just couldn't justify the expense of a diesel for a truck that will travel less than 1000 miles a year. If I are going to racking up thousands of highway miles a year with it, that's another story. And gassers can be quieter, and my wife HATES the smell of diesel exhaust - but otherwise she's perfect!
My 3 cents
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