1999 jeep cherokee 2006 engine swap?

This is the first Jeep for me. I have a lot of experience with other engines but not with the 4 liter jeep. That said , I am going to replace a 1999 jeep Cherokee Sport's engine with a 4 liter long block out of a 2006 Jeep Wrangler.

I would like to use all of the 1999's external parts (intake, exhaust etc)What problems will I run into if any?

Thank for your help:)