Hobby Stock Rules 2025
2025 Hobby Stock Rules
**Transponders are Mandatory**
#1 – Body
1.1 Any American made rear wheel drive car. All frames must be stock OEM. No
aftermarket or homemade frames.
1.2 Full frame cars can replace rear frame after kick ups with 2 x 3 tubing.
1.3 Stock unibody cars must use 2 x 3 tubing from front clip to end of chassis
1.4 No torque arm cars.
1.5 Minimum weight of 3000lbs with driver at completion of race. Track scales will be
used to determine
weight and will be final.
1.6 4-point roll cage minimum with 4 door bars on drivers side, front and rear hoops 1 ½”
.095 tubing.
1.7 Stock steel bodies, aftermarket steel or aluminum bodies allowed but must remain
stock appearing.
Fiberglass hood allowed, max 5” spoiler allowed. No late model or prostock looking
bodies.
1.8 Must run stock appearing nose. The tail piece is optional.
1.9 If car has replacement floor or firewall it must be minimum 22-gauge steel.
1.10 All cars must be presentable.
1.11 Drivers Door intrusion plate mandatory.
#2 – Front Suspension
2.1 All suspension and steering components must be OEM and in stock
location, with the exception of steel tubular non adjustable
replacement upper control arms. Lower control arms must be stock
equal length for that chassis. Aftermarket stock upper mounts are legal.
2.2 Steering quickeners allowed.
2.3 Spring cups or wedge bolt allowed, must be welded.
2.4 One non-adjustable non rebuildable shock allowed per wheel.
Shock option only (Afco 14 series or Pro WB Large Body Shock 2.00
Diameter) .Front shocks externally mounted allowed. Stock front
mounted shock allowed (Afco 1020,1021,1022 or Bilstein AK1043,
AK1051, AK3050F, AK3060F, AK4040F, AK5555F, AK6565F). Rear shock
must be + or – 1” from stock location.
2.5 Racing springs allowed.
2.6 Chassis components must be the same as chassis being used.
2.7 Jacking bolts and adjustable spring buckets must be welded. No chains.
2.8 Wheelbase 108 inches + or – 1 inch.
2.9 No bump stops on any shock (internal or external) or anywhere on the chassis.
#3 – Rear Suspension
3.1 Leaf springs – Chevy or Chrysler springs allowed.
3.2 No pull bars, No 3 link, No pan hard or j bars. No chains
3.3 Shackles or sliders allowed.
3.4 May run Ford 9” with bolt-in axles or full floaters allowed. No gun drilled axles. No
wrap up style axles. Both axles must measure the same diameters.
3.5 Aftermarket upper and lower trailing arms (stock replacement, non-adjustable only).
Equal length for both sides. No weight on or in the rear axle tube or suspension parts.
3.6 14” max Racing springs allowed.
3.7 Jacking bolts and adjustable spring buckets must be welded.
3.8 Rear end mounts must all be in stock location, no exceptions.
3.9 All suspension components must be in OEM locations.
3.10 Steel spool only, no lockers or traction control components.
3.11 Rear lower control arms from the bottom of the axle tube to the
center of the control arm bolt – 4 inches max.
3.12 May add 2” to the top of the rear spring buckets. Must have
stock spring buckets and cross member.
#4 – Engine
Option I – Factory sealed 602 GM crate with a box stock 4412 carb or
Rochester 500 cfm carb. No HP or XP carbs. Carbs must pass tech tools.
Motor must have factory seals only.
Option 2 – Open motor, all engines must remain stock stroke
configuration for manufacturer and cubic inch. Stock replacement
cranks unaltered allowed with minimum 48 lbs.
4.2 Flat top or dished pistons only, flat tops must be 2 or 4 valve relief.
Must use 5.7 I-beam or H beam rods. No billet or aluminum rods. No
part of the piston may extend above the deck surface of the block
4.3 Max overbore GM 350 .060, Ford 351.060, Chrysler 360.040
4.4 Stock production blocks only.
4.5 Cast iron stock production heads only. Vortec 906 and 062 are allowed.
4.6 No race flow or undercut valves. Max valve 2.02 intake 1.6 exhaust. No titanium valves
allowed.
4.7 No porting of heads or intake.
4.8 Screw in studs and guide plates allowed max 3/8 stud, no stud girdles
4.9 No roller cams, no 4/7 swap.
4.10 Engine must be in stock location. The fuel pump must be ahead of
the cross member.
4.11 Factory stock distributor, points or HEI allowed. Welding
advance allowed. No circuit board modules. Must remain factory
firing order.
4.12 12- volt system only.
4.13 Holley 4412 or Rochester 500 cfm only. Both must be box stock. No XP or HP carb.
Must pass tech tools.
4.14 1” carb spacer unaltered, No porting or tapering, No HVH style spacer allowed.
4.15 2-barrel unaltered intake or edelbrock 2101 allowed. On Vortec
heads – GM 602 crate intake only.
4.16 No lite weight crankshaft, minimum weight 48lbs.
4.17 Stock replacement headers or stock manifolds only. 1 5/8 or 1
3/4 tube allowed. Crossover headers allowed. No 180, no tri y
headers allowed. No merge collectors.
4.18 Mufflers mandatory, must exit behind driver. 3” pipes max, no 2
into 1 muffler or h or x pipes. Cant exit out of the door or body panel.
4.19 Site plug mandatory 3-6 inches from front pan on left side.
Exception – crate motor.
4.20 Stock stamp steel rocker arms only 1.5. No mixing ratios, no roller
rockers, no roller tip rockers. No stud girdles.
4.21 Aluminum water pumps allowed.
4.22 No titanium valves.
4.23 No Evac system.
#5 – Transmission, Bellhousing, Driveshaft
5.1 Any automatic or standard transmission allowed. No direct
drives, burt, falcon etc Standard transmission must have steel
bellhousing and stock or stock replacement clutch and flywheel. No lite
weight or triple disc. Automatic minimum of 10” torque converter
functional.
5.2 Steel drive shaft painted white only.
5.3 Drive shaft loops mandatory 6” from front u joint and
another in middle of driveshaft.
5.4 All gears must work.
#6 – Brakes
6.1 4-wheel brakes mandatory.
6.2 OEM steel calipers only.
6.3 Aftermarket master cylinders allowed.
6.4 Remote brake adjuster are allowed. No shut offs.
#7 – Tires and Wheels
7.1 Steel wheels only with maximum width 8”. Bead lock allowed.
Aluminum wheel covers are allowed, must be bolted by a minimum of 3
bolts.
7.2 No wide 5 hubs.
7.3 1” lugs are mandatory.
7.4 All season DOT tires only. 235/75/15 max size. Grooving and sipping allowed.
IF YOU WANT MORE – BUY A STREET STOCK
#8 – Safety
8.1 Aluminum racing seat mandatory. Must be mounted with
minimum 6 bolts safely (subject to tech)
8.2 All cars must have window net. Window net must be up and
secure during racing.
8.3 All drivers must have a working one-way radio on the 454.000
frequency in use at all times when on the track. Only communication
with driver allowed is from a track official.
8.4 All cars must have some form of tow chain front and rear – mandatory.
8.5 Ballast must be mounted securely with at least grade 5 bolts and
painted white with car number on it.
8.6 Helmet must be at least Snell 2015 or valid SFI 31 1/2005 label.
8.7 Seatbelts SFI 16.5 or 16.1, not to exceed manufacturers
expiration date.
8.8 All fuel cells must have rubber flapper valve.
ALL OFFICIAL AND TECH RULINGS ARE FINAL!!
While the above rules offer a good guideline, not everything can be covered
by a written rule. If you have any questions ASK FIRST. Any non-covered part
can be deemed illegal at any time. Anything not covered in the rules is not to assumed legal.