Welcome to the forum. You may have some challenges putting a 4bt into the 1st gen Ranger. Probably has been done but I suspect it will be a tight fit. First off, is the truck 2wd or4wd? The original 2.9 weighs just shy of 300 lbs. The 4bt will weight close to 750 lbs. Will need some substantial suspension upgrade. Next will be what transmission. And what differential(s). A stock 4bt will have near double the torque of the 2.9. Don't worry about HP. I assume this is not a cost limited project. Most of our guys do their own rebuilds. You could take it to Cummins. They have a shop in Charlotte NC and may have one in SC. If you are wanting more power than stock they probably wouldn't be the best choice. Do you have the engine serial number of your engine? If so, I can look up some info. Most shops will charge around $4000 for a complete long block rebuild. That does not cover items such as injection pump or turbo. If the head is cracked and needs replacement that number will go up around $1000. You'd probably want a better turbo if yours has the old H1C model. Around $800 and up for a good replacement. If the injection pump needs rebuilding that can run around $900 or more. You'll want a higher RPM governor spring in it. That part is cheap. Rebuilt injectors if needed can run around $80 each. There is nothing cheap about diesels.