Sporkosophy, on 04 April 2012 - 09:19 AM, said:
It would make sense given the fluff behind replacing the internal structure.
It also raises the question that I didn't see answered: can you change from one armor type to another (from standard to ferro), or one engine type to another (from standard to XL) within the variant. Changing this alters the critical structure pretty significantly, so I'm going to guess not.