A quick run down of the levels:
Class A Refit (Field): Allows replacement of one weapon with another of the same category and with the same (or fewer) critical spaces (including ammunition); for example, replace a medium laser with a medium pulse laser or ER medium laser, or replace an AC/10 with an LB 10-X AC, and so on. Additionally, changing a weapon's location or facing falls into this category.
Class B Refit (Field): Allows the replacement of one category of weapon with another class of weapon(s), but with the same or fewer critical spaces (including ammunition); for example, replacing a machine gun and ammo with a small pulse laser, replacing a Gauss rifle with two large lasers (as they're both the same class and have fewer critical slots), and so on.
Class C Refit (Maintenance): Allows replacement of one type of armor with another (all locations); for example, replacing standard armor with ferro-fiberous. A Class C refit also enables replacement of a weapon or item of equipment with any other, even if it is larger than the item(s) being replaced; for example, replacing an ER large laser with an LRM-10 launcher and ammunition. Also allows modification of armor quantity and distribution, moving components, and adding ammunition or heat sinks.
Class D Refit (Maintenance): Permits installation of a new item where previously there was none, or to install an ECM suite, C3 system or targeting computer. May also change heat sink types (including those integral to the engine) or engine ratings (but not engine type). Also allows replacement of a location with a custom part. Assuming that Artemis IV FCS (not specifically mentioned).
Class E Refit (Factory): Allows changing the type of myomers installed or install CASE.
Class F Refit (Factory): Allows changing of internal structure type (all locations), engine type, gyro type, or cockpit type.
Not saying it should be forced, just saying try it out.
[Strategic Operations, pg 188]
See you out there.
edit: Added Artemis IV FCS
Edited by Danghen Woolf, 28 October 2014 - 02:27 PM.