• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

1989 4.0 to 1998 4.0 swap


NAXJA Forum User
hi all well i got a 1989 xj with an auto trans i am going to swap a 1998 4.0 from a cj with a manual trans what all am i going to need to change. i know i will need to change the fly wheel to a flex plate will the 89 flex plate fit the newer motor?? Will the old crank position sensor work for the new pcm or ecm what ever you want to call it.. oh i should say that i have the comp from the new motor i know the new motor had a manual trans and i have a auto trans but the 89 came with a comp just for the trans it wasn’t in the main comp. so i think the trans comp will work. so i wont have to get a new comp for the motor. i know the old motor had a off set fan but i have replaced the fan with a electric fan a while ago. so i can leave the none off set water pump on the new motor i just have to take off the fan blades. i see the throttle body is not the same it is different linkage i will make it fit also i am going to mod a 62 mm throttle body from a 5.0 mustang and bore the intake and the throttle body to a 63 mm i know i need to mount the combo trans and throttle position switch to work the trans and and i think the comp.. i think the old switch will work with the new comp. i am also adding a header and a cam I will be rebuilding the old 4.0 to make a stroker out of it.
and i will use the newer head and all comp parts.. i have # 15 ford injecters on my old eng i think i will need #19 or bigger injectors to make the stroker work also I have a Jacobs ignition and coil I will add to the new motor ....well is there any thing any one can think off that i will need to finish the motor swap???