I have a 68 coupe that I have torn down to rebuild it as a Restomod.  I would like to put in a 5.0 and a T5 Tranny for the drivetrain.  I have found a 94 GT with a 5.0 HO and would like to use that, but is that too new of an engine?  Somewhere, I heard that 93 was the cutoff.  

Are you planning on using the injection? If not take off the injection(upper and lower intake)and throw on carb and intake. As for the fuel injected engine it will bolt in with small block motor mounts. All the conversion stuff can be found on the net from windsor fox. At this moment im putting a 5.4 into a 69 with my friend. not much room in the bay Im also making my own headers(not fun)