I have a 1999 ranger 4x4 with a OHV 4.0, that broke a piston, when checking for a used 4.0 I was told it had to be from a 98-2000,
is there a reason a earlier 4.0 wont work if you swap intake and exhaust manifolds? and sensors, or is the block different?.
the reason I ask is I have access to a low mile 1995 4.0 cheap, but if it is too different it isn't worth it

 

Welcome to the forum

To use the 1995 4.0l you would need to get a new flywheel or flexplate as the 1997-2000 use 8 bolt, and 1996 and earlier used 6 bolt, if you have an automatic you may want to stick to 1997 and newer engine, as the 6 bolt flexplates tended to break, which is why Ford changed the crank to 8 bolt

The 1998-2000 4.0l and its computer used smaller exhaust port heads and different pistons to heat up Cats faster to pass cold start and warm up emissions, using the older 4.0l "may" cause engine to run a bit hotter, but this is a "may" not a "will" cause a problem

1990-2000 4.0l OHV info here: https://therangerstation.com/tech_li...0rebuild.shtml

 

Thank you for the quick answer and link.
well, that is exactly the kind of info I wanted. My truck is an automatic so the flywheel info is good to know.
And I never would have guessed the valve and piston change. I think I might look for correct motor

 

I have NOT heard of any issues but the 1998-2000 computer will run a more aggressive spark timing to meet emissions, so not sure the 1997 and older model heads/pistons would like that

Yes, if you use a 1997-2000 4.0l your current flexplate will work on the new engine