Here's your Grub Getter info, right off their website from last summer. Clearly, it's a stock class.

GRUB GETTER $1,000 to win on August 19th
GENERAL RULES – All vehicles must come to the track RACE READY. Car
number MUST BE BIG & EASY TO READ on both sides and top. All glass,
headlights, & taillights except windshield should be removed along with
other excess parts like spare jack, spare tires, old parts, trash, etc.
Interior must remain in stock condition. 4 & 6-cylinder cars, SUV’s &
minivans are eligible with a maximum of 22 feet in length. Stock fuel
tanks only. The ONLY added reinforcements eligible (but not required)
are an outside bar or plate to the driver’s door. No roll cages. Must
remove airbags. Can remove the catalytic converter but must fully
replace with pipe. THIS IS NOT INTENDED TO BE A RACE CAR!!! Tech
decisions are final.
• DRIVER EQUIPMENT – Must wear long-sleeves & long pants (fire suit
recommended). Neck collar is required. Helmet must be ALWAYS worn
while on track (even while in the infield).
• MEETING – There will be a driver’s meeting at the event. Attendance
is MANDATORY