(going by memory here)
Swift Wind Scout Car - often refitted with ICE
MASH - See above, unless used by well-off units
Packrat - See above
J. Edgar Hover Tank - Very rare
Mobile HQ - As MASH
Hunter - You got me here, it doesn't even need the SFE!
Drillson - Originally ICE, retconned to SFE when TPTB noticed it was way illegal
Manticore - Mostly well-off units, rated as valuable as a mech
Rommel/Patton (NEW designs in 3025, no less) - And SFEs was a major problem for production and getting them into the field
Von Luckner - Often sacrificed to keep mechs working (also does perfectly well with an ICE)
Schreck - Very uncommon
Of course units that already have mechs will be necessity have the support to handle fusion engines, so they can have at least some fusion vehicles as well.