Pro Stock 2011

Naturally aspirated class. No power adders permitted. Stock bore spacing only.

Body and chassis:
- Lexan/plexiglass window replacements permitted but must appear stock. No visible bracing,
  screws, rivets, etc. permitted.
- Functioning lights required.
- Light weight body panels allowed
- Stock style front suspension required. Bolt in replacement components allowed. Non O.E. style
  components subject to weight adder.
- Ladder bars and 4 links permitted. See weight adders below
- Stock fire wall and location required. Modified or non stock firewall location subject to weight
  adder.
- Small rear wing permitted
- Forward facing hood scoops permitted. See weight adders below

Exhaust:
- Mufflers required. Must be commercially available units, no home built mufflers. No gutting of
  mufflers permitted. No inserts style mufflers
- No max pipe diameter

Induction:
- Any type permitted. See weight adders below

Cylinder heads:
- Non Conventional Big block heads add +.25 per ci from 14-17.99 degree valve angle and add 
  +.15 per ci for 18 and up   (N/C heads include Buick, Big Chief style heads, etc.)
- All canted valve small block cylinder heads + 50#
- 10 to 14 degree heads +50#
- 15 to 17 degree heads +25#
- 18 to 20 degree heads -50#
- 20 and over degree heads -100#

Big Block Prohibited head list:

Chevrolet
- Profiler 12 degree Hitman #184
- Brodix PB-1200 and PB-2005
- Dart Big Chief II 11degree #18500000
- RMRE 12 degree Raptor
- CFE DRCE 4.840 Bore
- CFE Big Chief 10 degree

Ford
- Profiler #205
- Blue Thunder Thor
- IDT Eliminator Series
- Ford C-460
- Ford E-460

Mopar
- NRC Heads (Predator Heads)
- B1 Top Sportsman
- Indy 600-13

Some non conventional heads will be assessed on a per case basis.

Tires:
- 29.5x10.5W" maximum slick

Transmission:
- Any automatic or manual transmission
- Any converter OK but all shifts must occur manually by the driver. No automatic shifters

Base weight:
- 2550# small block minimum base weight for 399ci and smaller +3# per ci above 300ci to 
  399ci
- 2600# small block minimum base weight for 400ci and larger +3# per ci above 300ci to 470ci.
  Add 2# per ci over 471ci
- 2650# big block minimum base weight+3# per ci above 300ci to 470ci. Add 2# per ci from
  471ci to  632
- Maximum 632ci

Weight adders:
- 100# weight adder for clutchless “Liberty type” manual transmission
- 50# weight adder for clutchless “Lenco type” manual transmission
- Ladder bars permitted
- 4 links allowed with 25# adder
- Two carbs add 100#
- Split dominators add 25#
- Bruno/donovan +25 (4 speed) +50 (5 speed)
- Sheetmetal intake add 50#
- Wheelie bars add 50#. 60” max length (axle c/l to wheelie bar wheel c/l)

Weight break:
- 50# weight break for non forward facing (cowl induction style) hood
- 50# weight break for non W rear tire. Must be 10.75” tread width or smaller to qualify for
  break. Will be measured via a go-no go gauge during tech.
- 50# weight break for stock style rear suspension (diagonal 4 link or 3 link , Torque arms)
- 150# weight break for 4.6L/5.4L Modular Engines
- 100# nostalgia (1981 and older ) body style/truck (mustang fox body 79-81 runs at base
  weight)-true back half cars only, full chassis cars not eligible for break
- 50# weight break for 2 speed auto transmission
- 75# weight break for leaf spring equipped entries- must transmit all power through the eye of
  the spring

Safety:
- HANS (or equivalent) device - Mandatory

Fuel:
- Gasoline only

If you are building a race car and you are unclear about rules concerning your class, please contact us.

The OSCA reserves the right to impose penalties for rule infractions and on items which do not represent the intent of the class entered.

Rules are subject to change without notice. If in doubt as to rule interpretation please contact us for final ruling.