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Discussion Starter #1
Hello,
I finally decided to use the Dodge D60/D70 from my W350 in my '63 Jeep J300. The tag in the rear diff. says the gearing is 3.07, which makes the front axle a D61.

My plans are to use these axles along with a NV4500 and a 4BT with the rotary pump. This truck will be use to haul medium sized loads and (very) occasionally tow a 4400 lb car (a 1966 Olds Toronado). With 31" tires, this combo puts the RPM's at 1600 at 65MPH and 1800 at 75MPH. This would make for a nice highway cruiser, but considering the modest output of the 4BT, how bad is it going to be as an occasional tow vehicle?
Thanks,
Mikel
 

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actually I think that is honestly perfect gearing IMO. I would love to have that gear ratio.. Again slight bump in fuel and turbo and it feels like a V8 on the highway I would say with minimal loss of economy... Won't tow like a real tow rig but you will be fine :)
 

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Discussion Starter #3
Can 160HP/400ft-lbs be achieved easily with the rotary pump? Will vibrations increase significantly?
Thanks,
Mikel
 

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If its only going to be occasional towing you can always run in 4th at say 60-65 and turn about 2100-2250. I'm planning on running 3.08 with a 90 F150 with a ZF5 and 33" tires. It should be right at 1700 @ 70. If I tow I can run in 4th at 2080 @ 65.
 
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