People have used NT pistons in the 4g63t motors with very bad results. They are not the same metal. They will not withstand boost and higher temperatures. Come on, this is Mitsubishi. They will save money any way they can.

Enjoy that engine now, because the pistons won't last long.


Directly from VFAQ:

Has anybody ever installed 2G pistons in a 1G engine?
Has anybody ever installed 1G NT pistons in a 1G T engine?

This has been done on occasion. 2G turbo pistons are a higher compression ratio (8.5:1 instead of 7.8:1) and are capable of delivering more power, with a higher probability of detonation. The same should be true of 1G NT pistons (9.0:1), but the NT pistons are not designed to withstand the stresses inherent in turbocharging, making the 2G turbo pistons the next best choice.