Here's the group that runs out of Cecil County, MD, FWIW. Compared to some of the other NSS orgs, I think these guys are fairly open to what styles of cars are accepted. Even my "post-muscle car peak" 1973 Challenger is still 50 years old now, and they accept certain models up thru 1975. IIRC, they generally get 30+ cars at each event.

United Nostalgia Stock/Superstock Rules
Effective Jan. 1 2022

1. If time allows we will have a driver/crew meeting prior to first round of qualifying. Attendance is not mandatory. Listen for track announcements for when and where.

2. Cars that qualify torun this series must be American made production vehicles, between 1955 and 1975. Cars must use engines consistent t o manufacturer. (Ford/Mercury must h a v e Ford engines; Chevrolet - Chevy
engines; Plymouth and Dodge - Mopar engines; Pontiac- Pontiac engines etc. etc.). Both big and smal block engines allowed. Internal engine modifications allowed.

3. Cars must appear "PERIOD CORRECT"to the following classes: Stock, Super/Stock, Factory Experimental (F/X), Altered Wheel Base (AWB), and JuniorStock. Minor body modifications are allowed, such as "cowl" type hoods, period correct fiberglass body panels, and period correct hood scoops. Pro Stock, Snorkel or Tunnel Ram Hood Scoops are NOTACCEPTABLE. Al cars must retain factory correct appearance, including door handles, bumpers, grilles, head and taillights, etc. Said items can be of fiberglass/lightweight material (matching original pieces). Al cars must be naturally aspirated. (i.e. NO superchargers, turbochargers, nitrous oxide, or other power adders allowed.) Period correct appearing port-style fuel injection allowed on F/X and AWB cars only. Al forms of Starting Line Controllers including pneumatic and mechanical are prohibited. Full tube chassis cars are strictly prohibited.

4. All cars, drivers, and driver's safety equipment must meet N.H.R.A. rules, and pass technical inspection at the racetrack. Throttle stops, delay boxes, stutter boxes, cross overboxes are strictlyprohibited. fI these items are ni your car they cannot be used. Trans brakes and two steps allowed for stick and automatic cars.

5. All competitors must report to appropriate staging lanes when called in atimely manner. Al races will be run using a .500 sportsman full tree. Qualifying positions will be determined by driver's bestreaction time recorded duringqualifying and/or elimination rounds. "Deep staging" is NOT allowed. If yourcaris deep staged either during qualifying or eliminations, as thestarter activatesthe switch your sideof the tree wil go immediately red. No elapsed time wil be recorded. (This is known as the "Blue Light Setting")

6. Something new has been added recently tothe starting system. It is known as "Tru Start". Instead of the first to red-light being the loser, the system wil pick theworst red-light (if both cars go red) and the win light on the scoreboards wil show the winner of the run. The tree at the starting line wil show red in both lanes. Now fi only one car goes red it may get a little confusing. Please ask any track official to clarify it to you.

7. Drivers wil select their "dial-in" for eliminations (i.e. 10.26, 13.57, 8.96, etc.). "Dial-ins" can be changed between rounds. "Dial-ins" must be posted on the side window that faces the tower. "Dial-ins" must be clear and legible for tower and track personnel to enter yourcorrect "dial-in". "Dial-ins" cannot be changed once vehicle si past the "ready line" (prior to the water box) during eliminations. "Dial-in" limited to 14.00 and lower (faster). Al drivers MUST verify that "their" correct "dial-in" si on the score board or the small indicators behind the starter before pre-staging. Once you stage your car the "dial-in" on the score board si yours whetherit's the correct one or not. There will be NO reruns because an incorrect"dial-in" wasentered.

8. Eliminations will begin with random pairings. The #1 qualifier receiving a "bye" run if there are an odd number of competitors in the first round. In subsequent rounds fi odd number of cars are scheduled, the car with the best winning reaction time will be pulled aside. If odd number of cars do showt h e car wil get the bye, if even number of cars show, the bye car wil run the last car in the lanes and have lane choice. You wil only get one bye run per race. Random pairings wil continue each round, until the field si reduced to sixteen (16) or less cars. At sixteen (16) or less cars, the pairings will be run on a sportsman ladder. The ladder is generated by the computer in the tower.

9. Acceptance for participation and competition is based solely on the Event Director's discretion. Inappropriate or indecent conduct will not be tolerated. This series was created basedsolely on the idea of having fun, "Run By Racers For Racers." so let's al have fun and be safe, out there.