My issue is I thought a 401 and a 290 had the same block deminsions when it comes to fitting in a vehicle. I pulled a 401 out of a 72 J4000 and a 290 out of a 72 CJ-5 and went to put the 290 in the J4000 and it appears it is to narrow by about 4 inches. Does anyone know about this. Can I just change motor mounts and make it work. The mounts appear different but they measure pretty close to the same at the top of them. Is the 290 a narrow block than the 360 or the 401. The J4000 came stock with a 360 and has a factory reman. 40 in it.