Alright i'm new to this forum. Like ten minutes new. I have a 1990 cherokee laredo with 4.0 it runs and drive like a dream but the rockers are completely rusted out. The doors are rusted through and over all is pretty ugly and not a solid body. I just recently purchased a 2000 cherokee sport also a 4.0 with a beautiful body and interior but the motor is seized up. Both are automatics. I bought the 90 for 350 bucks and the 2000 for 1000 so I think i'm doing pretty good so far. I know the EFI is totally different but not much after that. So can I take the older block out of ole rust bucket and swap the new head and intake an everything else from the 2000. I'm not sure what is all different between the engines but I was hoping the block had not changed at all over time. If anyone has done something like this please give me some info and tell about the differences between the two.