Hijet 1.3i 16V 1999 HC-E engine into Piaggio Porter 1.3i 16V 2006?

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A pal has a Piaggio Porter 1.3i (2006) and would like me to replace the engine with one he has from a Hijet 1.3i (1999) with engine code HC-E. Does anyone know if this is feasible? The engines look very similar but the Porter is from 2006 and after 2004 they did not share exactly the same engine as the Hijet 1.3i. We have the ECU for the Hijet engine just in case.