I am putting a '92 Ranger 4.0 in my '96 and I am having motor mount issues. You will also need to swap over the cam position sensor from the '95 engine to the '91 but you need an alignment tool to do it with.
With the exhaust, you should only have to swap the passenger side exhaust manifold because of the EGR.
The upper intake should be all you have to swap over, but I am swapping the lower on as well because I see evidence of a small coolant leak so I will change the gaskets at the same time.
You may also need to swap over the oil pan to the 91 motor if it is different. The only difference between my 96 oil pan and my 92 oil pan is the oil level sensor on the 92, the 96 does not have one.
I'm hoping 410Fortune will see this thread because he has done a lot of 4.0 swaps and knows more than I do on this subject.
