Will a 99 ranger 4x4 trans 4.0 fit v8?

No, a 99 Ranger 4x4 transmission designed for the 4.0L engine will not fit a V8. The V8 engine produces significantly more torque and horsepower than the 4.0L, and the transmission is not designed to handle that increased stress. You'll need a transmission specifically built for a V8, and even then, it's a major undertaking that usually requires significant modifications to the vehicle's frame and drivetrain.