hello. I am looking for anyone who can tell me wether or not u can swap a jeep cherokee motor for a grand cherokee motor

 

Need year of the Jeep... and year of the donor to give you the right info 4 Ltr Renix, 4.2 HO Details Details Details

 

I was told the donor engine (grand cherokee) is a '94 and the cherokee it's possibly going into is a '91 both 4.0 L But is there any way to be sure of the year of the donor by just the numbers on the engine?? other than that I don't have much info