i am doing some research for a friend. he just recently got a 2000 cherokee with a blown motor. he needs to know if there has been any changes to the 4.0 block. i have been looking and so has he and the only think we have come up with is its destributorless. which we already knew. now if this it can an older block be used with all the newer wiring?

as far as i know, its a no, if its distibutorless, then the older model is going to have a galley for the distributor, if i am wrong someone will correct me. but i belevie they used the same engines from 91-2001?

87-90 renix era....In 1991 Chrysler redesigned the RENIX engine control computer and raised the intake ports approximately 1/8-inch (3.175 mm) for a better entry radius. Chrysler also enlarged the throttle body and redesigned the intake and exhaust manifolds for more efficiency, and the fuel injectors were once again replaced with higher flowing units. The camshaft profile was also changed. The net result was an engine that made 190 hp and 225 lb·ft of torque. Badging on most Jeeps equipped with this engine read "4.0 Litre HIGH OUTPUT." The new cam profile combined with altered computer programming eliminated the need for an EGR valve and knock sensor, but made the engine more sensitive to alterations, especially where emissions are concerned.

Small changes were made to the cylinder head for the 1995 model year. In 1996, the engine block was redesigned, and a new strengthened unit was then used. The new block made use of more webbing cast into the block, and a stud girdle for added rigidity of the crankshaft main bearings. The cylinder head was again changed around 1998 to a lower flowing, more emissions-friendly design. Engines installed in 1999 Grand Cherokees carried the Power Tech name, which had been used intermittently in prior years. The name was subsequently passed on to 4.0s in all Jeep models.

so no they didnt use the same engines...I6 motors yea but they did change. as for the 4.0 with coil packs...no distributor im not sure if they are compatible with older renix engines as far as coverting a renix era engine with a newer model I6... hell i hope this helps you some.:flipoff2: and if im wrong im sure someone will correct me too i would just buy a crate motor for it to skip the hassle and unsure thoughts of how good of shape a donor motor is even if it is low mileage....