Yep, the 4.0 is just a bored and stroked 2.9. I understand that the exterior engine dimensions are the same. I think going with the Ford engine is going to be my best bet. That engine was used in Explorers, Rangers and Aerostars, so they are plentiful. Also found I can use a Mitsubishi Starion external fuel pump that will pump up to 55 lbs for the injection. This way all I have to do is build fuel lines from the stock tank to the engine and back. I should be able to use all stock running gear in this truck to keep it cheap!
That thick leaf on the bottom of the spring pack is the one I take out of my stuff. Only thing I have overloads on is my 3/4 ton truck. I replace it with 2 regular leaves, one about the actual length of the overload and the other about 18" long. Do not use any spring leaf less than 18" long unless they are custom built with thinner material (like Nationals or Deavers) otherwise you create stiffness and no flex. I took the overloads out of my sons 1991 S-10 extracab 4x4 added the 2 leaves and took the front sway bar off. Raised the front a little by tightening the torsin bars and man what a difference! No more rear pogo sticking going down dirt roads! Those back springs flexed baby! And during 4 wheeling the suspension travel was increased greatly. Thanks again for turning me on to the Cologne engine! I snagged this Mazda because it fits me with the standard cab. The Toyota standard cab is not comfy for me to drive very far. I am 6'1" 225lbs. Otherwise I would be doing a Toyota, however nobody has ever offered me a free Toyota!