Could it be possible to replace a 2.5L with a Wenkle from a RX7?

 

You would have plenty of room for a Wankel. Be aware that a Wankle is small and powerful but it has poor fuel efficiency. Power is also achieved at higher RPMs which is not what you want in a truck.

A 2 rotor would be a bit anemic in power even with a turbo system. You would need to look at 4 rotor system. A 4 rotor turbo would give you the power you wanted but you would probably need to add an auxiliary fuel tank as the range of the stock fuel tank would be 100 miles or less - it is a major gas hog.

There are better transplant engines out there.

 

Where on earth are you going to get a 4 rotor Wankel aside from engineering one from scratch?