the other problem that you might come across is that on an eclipse, the turbo sits below the manifold....so if you could get it to work, then the turbo will sit ontop of you oil pressure sensor, crank sensor, and the down pipe will come out in the spot your axel should be

 

ok but want the 4g63 motor fit in the neon

 

i think with enouph money anything will fit in a neon

 

the 4g63 will physically fit, but it wont be a simple swap by any means....not to mention the exhaust and intake sides being opposite