I have a 2005 Mazda B4000. V-6 4.0. What V-6 Ford motor will interchange with it without alot of extra work?

I have a 2005 Mazda B4000. V-6 4.0. What V-6 Ford motor will interchange with it without alot of extra work?

None. All will be a lot of work, but some will be worse than others. The Ford/Mazda relationship ended a long while ago, so there's no reason to expect any Ford V6 to fit any better than any other V6 from another manufacturer.

At the very least you'll need to fabricate suitable engine mountings, a bellhousing adapter plate, change or adapt the flywheel, make major changes to the vehicle wiring loom, exhaust system, reroute fuel lines and other connections to the engine. At the worst you'd be also be making bodyshell alterations, transmission and driveshaft changes.

The same engine out of a ford ranger