can be done but not easily, I looked into it when I had my 4 banger mx6 and it would take alot of fabrication but yes it has been done.you can put a FE3 motor from a first gen mx6 into a gen 2 mx6 i seen pics of it done.. you might as well just turbo the 4 banger in your car...
I dunno everyone is saying it's going 2 cost a fortune 2 rebuild internals etc etc.. i just found a klze fully build bored bigger pistons rods etc etc 4 around 3000 bucks but she's ready 2 be beatin with boost but it pays 2 play man.. just gotta look around what ppl are selling now a days i was going 2 do the run around but now i found someone selling a fully built ZE saves me the trouble in running around taking it to a machine shop getting it there building mean while the work is al done for me unless you want 2 rebuild it yourself & @ this point i dont really have the time 2 build a motor & run around town with my head cut off trying 2 build this motor just my 2 cents~if going for a ZE, make sure to get new O2 sensors, I think that was the key to my pass. and do all the common sense stuff like a long drive to warm up the cat, high octane gas, and if you can run it on gas mixed with ethanol I've heard that works.
If ur looking to drag race, the ZE will do high 14's n.a. with all the bolt on goodies, not that I've done it but I'm new so I kinda suck, my best 15.8 with bald tires lol.
if money isn't really an issue grab a DE and slap a turbo on there, apparently the lower compression means it's better for FI. But if you do turbo, 7 psi is as much as you would want to go on stock motor. you could go crazy and build the internals and maybe go 14+ psi but thats sinking a gold mine into it.
All in all just doing a ZE swap is still a huge difference, a whole new car and totally worth it.
P.S. My buddy has 2 sitting in storage I'm sure he would cut you a deal if you wanted.