Well Dave.. like all things racing, how much modification is allowed is as much you get away with till your caught !! :-)
The hot Intrepid was a 94 running a 3.3L, as far as I could tell, he had a bone stock engine in there.. nobody is running an 02,03,04 car.. mostly early to mid 90's cars.. I'll be pushing the envelope in what can be built within budget gunning for a 97/98 Camry or 95 Avalon.
Below is the offical rules.. but I can tell you we also run in the Pony Stock Class (which is a 4 cylinder, FWD-auto, 2V SOHC class) and guys were stiffening frames, putting in lowering shocks/struts, putting in 8 to 10 degrees camber, elevating compression, putting in hot cams, getting heads ported..
For 07, I know the Intrepid owner upgraded to a 3.5 H.O. vehicle.. which books out at 225hp/215lbs torque and is talking a lot of smack.. and I mean a ton a SMACK. I want to shut him up in the worst way and with all the knowledge and experience the Toyota community has.. I think we can get it done.
--- full rules ---
Notice # 1: The Pure Stock division is new for the 2006 season. It was added in an attempt to provide a more affordable option to racing. Due to the many makes and models available for use, restrictions and minor changes may need to take place during the season as we learn more about this new division.
Notice #2: Any interpretations of the rules are left to the officials, whose decisions are final. Just because it is not written, does not mean you can do it. The two words to remember in this class are STOCK ONLY. In the event a car is deemed to have illegal parts the car is subject to being banned from all future race events at Spartan and Springport Motor Speedways. The driver is subject to loss of points to date, all prize money for the night and suspension from property.
Notice #3: If you are considering building or purchasing a Pure Stock we highly recommend you receive pre-registration approval prior to doing so. There may be cars that have been permanently suspended Spartan because of rule infractions.
A. BODY AND CHASSIS:
Any American made FWD V-6 model (no convertibles, 2 seat coupes, super charged or turbo).
The vehicle must remain in its original form. No alterations are allowed unless specifically stated in these rules. (See notice #3)
a) Wheel base minimum: 104.5"
(NOTE: Small-bodied cars not allowed. If you're unsure, call first)
b) Weights: (post race with driver) 3000 lbs.
(3800, DOHC, multi-valve add 100 lbs.)
c) Bumpers must be stock appearing.
d) Tow hooks are required.
e) All doors must be welded shut.
f) Rub rails are allowed (no sharp edges).
g) Must be able to open trunk and hood without use of special tools. Hood pins required.
h) Rear and side glass must be removed. Windshield may stay or be replaced with 1/8" thick Lexan. All other glass must be removed including but not limited to taillights, headlights, turn signals, mirrors, plastic, upholstery, carpet, etc.
i) Any after market add ons must be removed. Ex: trailer hitch
j) The battery may remain in the original factory location provided it is in a safe location and securely mounted. If the battery is relocated, it may only be relocated to the trunk area. Batteries mounted in trunk must be secured by (2) two 1" metal straps. No batteries mounted in driver's compartment.
k) Fuel tank to be mounted in trunk and secured with (2) two 1" metal straps (made for racing for fuel cells are recommended). May run plastic gas tank if it is located in front of rear axle, under floor pan and is fully covered with a steel skid plate. Fuel lines must run below floor pan. Tanks that are mounted in the trunk must have protective hoop and 10" of ground clearance.
l) Front fender inner liners may be removed.
m) No frame alterations of any kind allowed.
n) No adjustable shocks or struts of any kind allowed.
o) Must have stock floor plan to rear axle and all holes in fire walls must be covered with sheetmetal.
p) Must have battery kill switch mounted on "A" pillar.
B. ENGINES:
a) Stock only in stock location. No aftermarket parts.
b) Single exhaust only. Maximum 2.0" OD. Last 6" of exhaust must exit behind driver and be fully visible. No exhaust leaks allowed.
C. DRIVE TRAIN COMPONENTS:
a) Stock automatic only. Cooler are allowed.
b) Stock diameter working torque converter only.
c) No aluminum wheels. Steel wheels only, stock for that year, make and model.
d) 1" Lug nuts are required.
e) D.O.T. Street radials only. No bias ply, made for racing tires. Maximum width 235. No less than 60 series (no 55, 50, 40). Minimum tread wear rating of 300. All 4 tires and wheels must be the same size.
D. BRAKES:
a) Must have 4 wheel hydraulic brakes in working order.
E. SAFETY:
a) A four point cage with four driver's side door bars, three right side door bars and a 1/8" steel plate on driver's side door bars from front upright to rear upright and from top door bar to frame rail is mandatory. A front hoop may extend into the engine bay area. Tubing must be .095 gauge, 1.75" O.D. and must be padded around driver.
b) Made for racing aluminum seat, properly mounted is required.
c) A 5 point harness, properly mounted with a 3 year maximum date is required.
d) Driver's side window net with quick release is required.
e) A 2 lb. currently dated B or C type dry chemical fire extinguisher is required within driver's reach.
f) Fuel injected vehicles are required to have fuel pumps wired to stop any fuel from being pumped when engine is not running.
g) Steering wheel center must be padded. Quick release steering wheel optional.