1990-1994 4.0 , 4” piston options

[RangerJoeD]

Ive read multiple times about the abilty to overbore the 91-94 4.0 engines to a 4” bore to allow for better off the shelf piston selection...... Has anybody actually done this and what piston should I be looking for. Deck height, stroke, rod length and piston pin diameter have me guessing.... Any input would be appreciated.

 

[RangerJoeD]

I seen some pistons on the summit racing website that measure 3.992 ” , if all else fails I will use those.

 

[RangerJoeD]

Just updating my old thread.... Im curious if anyone has bored their early 4.0 engines to a 4" bore.... if so what did you use?

 

[woodyedmiston]

4.0 pistons

Go to the 4.0 forum site. In the right top of the page look for "search this site" click it and u will get a search bar. Put in something like "4 incn pistons " or "bore out the 4.0". U will find several strings discussing the topic