Intergrated,
I'm guessing at a 30% increase in torque and HP. The Dana 53 should be fine with the increase. The Dana 25 front axle will be OK because I don't EVER go off roading.. I only use the 4WD feature of my truck on loose fire roads and snow. The upgraded trans (T5) will be the weak link. They don't do well with more
than 200 lb ft of torque...They also wear out fast with hard use.
The hardest use this truck ever sees is pulling the grade on the freeway (5 mile @ Castaic, Grapevine South, Northbound 101 out of SLO). The 258 should be a great match for the weight (3,220
lbs) and new gearing. Here's the RPM/MPH in 4th (Direct) and 5th (.086 Overdrive)
MPH .. 4th RPM .. 5th RPM
50 ... 1937 ..... 1666
60 ... 2325 ..... 2000
70 ... 2712 ..... 2332
75... 2906 ...... 2500
This is with 4.88 gears and 235/85/16 tires (31.5" high)
Oh, and the truck weight will probably go up 50-100 lbs with the newer engine...
Last edited by Melon; 02/12/14 02:01 PM.
