I have a 2000 Cherokee with distributorless ignition. I have heard that with this the design of the head changed. Is this true? I also am interested in putting a header on in the future, are there any available. i know that it has pre-catalyitic converters and am planning on eliminating them for better flow and a future high-pinion axle swap. I appreciate any help in this matter.

 

Very little enhancements are available for the dizzyless 4.0L engines and I wouldn't look for a whole lot of these either since it ended it's run a few years after yours was built. The guys that do the aftermarket have not caught that there is a market yet and may not for awhile or at all. Sorry!!

 

Pacesetter makes headers. http://cgi.ebay.com/ebaymotors/Paces...spagenameZWDVW

that is for a pre-cat like you said, but if you do change it, they still make them for the non-pre-cat exhausts.