The piece is included in the KGP module, with it's Chapter H details in the footnote and on the counter. See below (information not given is blank):
Weight: Type: high-speed tractor BPV: -
Size: +1 AF: « Turret AF: «
OT: Yes cs: 6 MP: 18
RF: -
Dates: -
GP: Low GT:
MA: AAMG ROF: 2 B#: - IF:
BMG: - CMG: - AAMG: 4
SA - Am: - s#: - sM#: -
PP/T#: 13PP/T4
Notes: O
During the war, the U.S. Army desired to have all artillery towed by purpose-built, fully-tracked cehicles, but their supply could never meet the demand. One of the more commonly used types was the M4 18-ton High-Speed Tractor, which was designed and produced by Allis-Chalmers. Entering production in late 1942, it was used for towing the 3-in. or 90mm AA gun, or (with different ammunition racks and a small swing crane at the rear) the 155mm gun, 8-in. howitzer. The M4 utilized chassis components of the obsolete M2A1 Medium Tank, and was powered by a Waukesha 6-cylinder gasoline engine.
The US M4 18-Ton High Speed Tractor provided in KGPII should have a 4FF AAMG using the 12.7mm To Kill number with “2” ROF per U.S. Multi-Applicable Vehicle Note O. Revised counters for these and other counters from KGPII are included in Doomed Battalions.