diesel swap

hey guys i hope you can help. i have a bronco ii that im planning a build for, and my dream-money-no-issue build is to do a 2.8t Cummins. i think... still open to the 302/5.0/ecoboost/4.0 options im looking for good v8 power with great fuel economy and long time reliability. plus keep my 4wd...

I am looking into an 88 ranger and wanted some insight on what might be the cheapest, yet most efficient diesel to put in it. The ranger has a 5-speed trans in it that i do not plan to change if possible.