First reason that comes to mind is torque . The second is torque .
And the third is torque.
Its already set up for a small block and he has the 4.0 crank and OD trany . Its a no brainer . With the right cam and headers you should be able to get close to 500 ft/lbs at a reasonable rpm . I wouldn't mess with the Gear Vendors the OD in the trany should suffice.
