My son and I spent the day putting in the motor and surprisingly the 4.0 block is really close , almost identical to the 4.2. Had to do some customizing on one motor mount, coil mount , power steering bracket, etc. We fired her up and ran it a little just to get an idea of how much tweaking was going to be needed and this 4.7 is definitely a torque machine. I didn't do too much because its just open header exhaust right now but I think it's going to have plenty of power for us. I think tomorrow is probably going to be spent figuring out how to keep it happy with the little carter 2 bbl on it.