Will a 95 Head fit a 91 4.0?

[dan2222]

Got a 91 Ranger 4.0 that needs a head. Found a 95 that seems to line up just fine. Do you think it will work?

 

[AllanD]

Will the head fit? Yes.

but it is NOT the same, the combustion chambers are smaller on the later (1995-up) "Fast burn" cylinder heads.

even though if you look up compression ratios the later (1995-up) engines are specified as having the same C/R, because the later engines have a larger dish in the piston to compensate....

You CAN run the later heads on the early short block but you will increase the
tendency of the engine to ping.

IF OTOH you happen to live at high altitude, Casper, Cheyenne, Denver, Flagstaff, etc?
it's just what you always wanted....

but whichever way you want to go you don't want to replace just ONE, they need to be a pair....

AD