Ok I know I have a 4.0L in my 98. Decal on back shows V8i, I do know the V8i has aluminum heads and block. My fuel system is an SFI. I guess my question is what is the difference between the 3.9 and the 4.0L? And I've already heard .1L. Is it just a model year switch? I guess what's confusing me is when I look at RAVE it shows the V8i as a 3.9L.

 

market hype. They are both 3950 cc, bore and stroke the same. Pages from spec area of RAVE shop manual attached. I guess the older 3.9i had distributor, vs the GEMS coil pack in the rear set up. The 3.9 is rated for slightly less power output. So maybe a difference in cam duration. Valve lift is the same.

 

Cross bolted mains on the 4.0 too. Bigger main journals also.