2018 Pro Stock Rules

Pro Stocks continue to be an exciting division of Saturday night racing at Wiscasset Speedway!  The following rules are a continued effort by division participants working together for division growth with respect to car variations, affordability and fairness of competition. While we understand these rules may not perfect and may not encompass all cars, we request they not be interpreted as opportunities to cheat and/or discover loopholes to gain advantage.  We shall always welcome and work to accommodate all who respectfully meet the spirit of the rules and desire to join us racing Pro Stocks at Wiscasset Speedway.

12/1/17 Rules Set.


DRIVER SAFETY REQUIREMENTS – drivers must wear the following required items at all times while on the racing surface. 

  1. One or two piece long sleeve SFI approved fire resistant suit in good condition and free of rips, tears or holes.
  2. Fire resistant shoes and gloves.
  3. Helmet must meet or exceed the Snell 2010 standard.
  4. Face shield, glasses or goggles.

Highly Recommended & Encouraged not yet required but you know it’s coming 😊

  1. Head and neck support/restraint safety device.

Recommended not required

  1. Fire resistant underwear, socks, and head stocking.


  1. Interior area of car must be completely enclosed in respect to the engine compartment, track surface, tires and rear (fuel cell) compartment.
  2. Area immediately beneath the driver, floorboards, foot box and the vertical panels surrounding the seat area (front and rear firewalls and transmission tunnel) must be constructed of twenty two (22) gauge steel and be of welded construction.
  3. Other interior panels may be constructed of aluminum with a minimum of .040 thickness. Panel on right side of car may extend from the top of the transmission tunnel to a height of not less than six (6) inches below the window.
  4. Any bar within the drivers reach must be padded with an approved product. Pipe insulation will not be acceptable.
  5. Front and rear firewall must be completely sealed from the driver compartment with sheet steel similar in thickness to existing car structure and securely welded.
  6. All welds are to be of high quality and must completely surround the joint. Absolutely no butt welds or sharp edges anywhere.
  7. All steering wheels must have a center pad.
  8. Canisters, made of minimum twenty two (22) gauge steel, over fuel cells are required and must be located in back of the rear window. There must be a complete steel firewall between the fuel cells and the driver’s compartment. No holes will be allowed in the firewall.
  9. The fuel cell must be capable of being filled only from behind the firewall.
  10. Fuel cells must be securely fastened and protected if they hang below the rear bumper.
  11. A minimum of an eight (8) inch ground clearance between the bottom of the fuel cell and the race track itself is required. All installations will be subject to Tech Inspector’s approval.
  12. All fuel filters must be of metal construction. No plastic, glass or other material will be allowed.
  13. Five point quick release harness system in good condition mounted with three eighths (3/8) inch bolts minimum Grade 8 washers and locking nuts. These must be attached at two (2) separate points on the frame, equal distance from the seat back and not less than twelve (12) inches apart.  (See manufacturer instructions for details).  Sternum belts are highly recommended.
  14. Aluminum racing seat with right and left head supports. Seat must be mounted and attached securely to the cage. A support brace must be installed at the rear of the seat.
  15. Racing regulation window net with quick release attachment required to be securely installed on driver side window. Plastic, plastic brackets, tape, wire or any other makeshift window net creation and/or mounting devices will not be acceptable.  Window nets must be securely fastened at all times when car is on racing surface.
  16. Minimum three (3) pound fire extinguisher mounted with quick release metal bracket within reach of driver when belted in. Extinguisher must be operational with full gauge reading.  Plastic brackets, tape, wire or other makeshift mounting devices will not be acceptable.


  1. Template type body only.
  2. Must retain as produced shape and dimension.
  3. All bodies must meet 2005 or newer Five Star ABC templates for contours and measurements. All body configurations must be approved by Speedway management in order to meet the body configuration intent.
  4. No carbon fiber bodies or parts will be allowed.
  5. Cars must use fiberglass or plastic/composite front fenders. Reworking or trimming of the front fenders will not be allowed.
  6. Front noses should conform to the stock template and must maintain a minimum distance of forty six (46) inches from center of the front spindles to the front of the vehicle.
  7. The molded lower lip on the nose must remain intact. Reworking or trimming of the nose will not be allowed.
  8. The front of the hood and the top flange of the front bumper cover must measure a minimum height of twenty-two (22) inches from the ground level.
  9. Spoilers must remain in the original location at the rear of the body shell.
  10. All body panels must maintain three (3) inch ground clearance with the driver seated in driver seat.
  11. Full windshield may be constructed of a minimum eighth (1/8) inch Lexan and must be braced with two (2) braces to prevent any deflection and/or distortion at speed. Rear windows and quarter windows will be allowed and must be constructed with same material as windshield.  Rear window must be braced to prevent deflection.
  12. Minimum roof height is forty-seven (47) inches as measured from the ground in the center of the roof and twelve (12) inches rearward of the windshield. Cars must measure a minimum of forty four (44) inches in height at the top center of the rear window.  The rear window height at the top may not drop more than one (1) inch from center to either side.
  13. Maximum spoiler size six and one half inches x sixty (6½ x 60) inches. Supports or bracing in front of the spoiler will not be allowed.
  14. Spoiler must follow the contour of the rear of the trunk lid or body shell with a maximum height of forty one and one (41½) half inches measured from the ground to the top of the spoiler. No portion of the spoiler at its base may extend beyond the area where it connects with the body or trunk lid.
  15. Air flow control devises no higher than two inches may be applied to the rear window and deck lid. Such devises cannot be more than one inch high along the roof.
  16. Hood and deck lid must be tethered to the roll cage.
  17. Sharp edges or projections which could possibly cut tires will not be allowed.
  18. Lifting/towing chains or cables must be installed both at the front and the rear of the race car are required. Absolutely No Exception.


  1. Tubular steel frames are required. Round tubing frames will not be allowed.
  2. Must be square steel tubing a minimum of two inches x three (2 x 3) inches or two and one half inches x two and one half (2½ x 2½) inches and at least .120 wall thickness.
  3. Front and rear clip to be square tubing and may be .083”.
  4. One-hundred and two (102) inch wheelbase minimum.
  5. Maximum tread width sixty-six and one half (66½) inches.
  6. The front and rear roll cage hoop must have a minimum height of thirty eight (38) inches measured from the top of the frame to the top of the roll cage. 


  1. Water and a cooling additive only. No antifreeze allowed.
  2. Must have a minimum one (1) quart capacity sealed overflow container.
  3. Car must not have fluid leaks of any kind.
  4. Battery must be in a sealed battery box and properly secured.
  5. Modified exhaust headers may be used.
  6. Exhaust system with a muffler is required and must extend past the drivers compartment turning down toward the ground with the end of exhaust system under the race car, not out the side or the rear of the race car. Tail pipes must be angled at least forty five (45) degrees toward the ground.
  7. Engine exhaust system may be painted, coated, or wrapped with a high temperature coating.


  1. Any safe rear suspension will be allowed.
  2. Single adjustable shocks only with a common retail value not to exceed four hundred dollars ($400.00) each. Must remain completely unaltered with product number and manufacturer visibly identifiable.
  3. All shocks subject to claim by Wiscasset Speedway Management for four hundred dollars ($400.00) each at any time.
  4. Titanium parts are not allowed.


Engines must be positioned within the chassis as follows –

  1. Engine height – centerline of crankshaft harmonic balancer or equivalent, and must be located a minimum of ten (10) inches and maximum of twelve (12) inches to the ground.
  2. Front to rear location – maximum of two (2) inches from centerline of forward most spark plug to determine line projected between the front ball joints of suspension.
  3. Fly-wheel scatter shield must be used with single disc clutch when using a full fly-wheel.
  4. Ignition boxes and coils must be mounted on the upper right side of the dash and must be fully visible.
  5. No electric fuel pumps.
  6. A minimum of three (3) inch oil pan clearance to the track surface is allowed.
  7. Cars by-passing the dry sump system with an external oil pump for wet sump and having removed the dry sump hoses and tank, shall be allowed to compete without weight penalty.
  8. Cars using certified crate motors without a cam change will be allowed a fifty (50) pound weight break. Cam change engines will be allowed a twenty five (25) pound weight break.  These weight breaks may be adjusted at any time by Wiscasset Speedway management in the interest of maintaining competition parity.


  1. Custom manufactured motors must meet the following: American made engines only. No V6 engines will be allowed. No aluminum or other soft metal blocks or heads will be allowed. No stroking or de-stroking will be permitted.
  2. No dry sumps allowed.
  3. After market cast iron blocks allowed. Must retain all OE dimensions.  Blocks may be decked, lifter bores, resized or bushed.  May be bored up to .060”.  Maximum compression ratio not to exceed 11 – 1.
  4. Any cast iron twenty-three (23) degree head allowed. May be port matched up to one half (½) inch from the gasket surface.
  5. Intake manifold must be one (1) piece casting. May be port matched up to one half (½) inch from the gasket surface.
  6. Carburetors must meet specifications for the following Holley numbers: #4476; HP80540-1; #4412; or #HP80583-1.
  7. Epoxies or other devices to alter the air flow into the manifold will not be allowed. Two (2) .070 thick gaskets will be allowed. Maximum of one (1) inch spacer will be allowed.  Polishing, grinding or drilling holes in the body of the carburetor will not be permitted.  Choke horn may be removed with a square cut.  No taper or bevel may be cut into the body of the carburetor.  Boosters may be aligned but may not be changed.  Size and shape must not be altered and height must remain standard.
  8. Venturi area must not be altered in any manner. Casting ring must not be removed. Base plates must not be altered in any shape or size.  Idle holes may be drilled in butterflies.  Throttle shaft must remain standard and may not be thinned or cut in any manner.
  9. Any camshaft will be allowed. Solid lifters will be allowed.  Roller lifters or Mushroom type lifters will not be allowed.
  10. Any Flat Top piston with a minimum of two (2) valve reliefs will be allowed. Floating of the wrist pin is optional. Normal engine balancing only. No part of the piston shall extend past the top of the block or deck.
  11. Steels rods only.


  1. GM Fast Burn 385 – Part #12496769 or GM Fast Burn 400 – Part #8895804. Factory sealed crate engine package, complete from intake manifold, stamped steel valve covers with racing style breathers, and eight (8) quart dual kick-out circle track racing oil pan.
  2. Those competing with original Fast Burn 385 intake manifold#12366573 or #12496820 may upgrade to Fast Burn 400 intake manifold#12496822 only if no other changes except for camshaft, rocker arms and lifters have been made.
  3. #25534354 eight (8) quart oil pan or Moroso pan #21319 will be allowed with matching pick up assembly and utilized in factory form without modifications.
  4. The tracks listed carburetor rule may be applied or the use of Holly #HP80541 will also be permitted.


  1. Jericho 2-speed transmission will be allowed.
  2. 5-speed transmission will not be allowed.
  3. Transmission case must be of stock production OEM configuration.
  4. A minimum of two (2) forward gears and reverse gear is required.
  5. Clutches must be a minimum of five and one half (5½) inches.
  6. Aluminum spindles will not be allowed.
  7. Driveshaft must be painted white.
  8. Driveshaft loop required near the front of the driveshaft with material specification minimum of one-quarter inch x two (1/4 x 2) inches. Rear driveshaft loop is recommended.


  1. Steel racing wheels maximum ten (10) inches wide.
  2. All four wheels must have brakes.
  3. Only brake bias adjustments are permitted from inside the car cockpit.
  4. Wiscasset Speedway Official Track Tire = Hoosier 27.0/10.0-15 3035 and 26.5/10.0-15 3045.
  5. Wiscasset Speedway shall keep a registered inventory of tires for each Pro Stock team with all tires being registered to the car number. Pro Stock teams shall be responsible for their own tire management.  Wiscasset Speedway will not impound, manage or provide storage for team tires.
  6. From April 7th to May 4th, Pro Stock teams shall have the option to purchase a maximum of six (6) new tires to begin their registered tire inventory for the 2018 racing season. Beginning May 5th on actual Pro Stock racing events thereafter, teams shall have the option to purchase a maximum of one (1) new tire one week and a maximum of two (2) new tires the next week for their registered tire inventory.  A schedule shall be posted depicting which week allows for the one (1) tire purchase and which week allows for the two (2) tire purchase with no deviance.  Should the option of any new tire purchase not be exercised, the option is forfeited.  All tires shall be registered to the car number.
  7. Pro Stock teams arriving to race after May 4th shall have the option to purchase a maximum of four (4) new tires to begin their registered tire inventory and on actual Pro Stock racing events thereafter, shall have the option of purchasing a maximum of one (1) new tire one week and a maximum of two (2) new tires the next week for their registered tire inventory. A schedule shall be posted depicting which week allows for the one (1) tire purchase and which week allows for the two (2) tire purchase with no deviance. Should the option of any new tire purchase not be exercised, the option shall be forfeited.  All tires shall be registered to the car number.
  8. Should a tire be damaged during the race event, it shall be the responsibility of the race team to present the damaged tire that day and within a timely manner to Tech for inspection. All tire replacements must have a written record with Tech regarding inspection and approval for replacement.  Only tires with 50% or more tread will be eligible for replacement.  Replacement of damaged tires will be limited to three (3) for the season. No Exceptions.
  9. All cars are subject to random testing at the discretion of Tech, durometer testing will be conducted On Track after heats and features of the top five (5) cars. Failure to meet the 2018 division preset number (Right Sides 50 and Left Sides 45 with No Allowances) will be subject to penalty as follows: Heats – illegal tire(s) held at Tech for the remainder of the race event and not allowed again until cleared by Tech; forfeiture of heat points and feature start is rear of the field.  Features – Full DQ with illegal tire(s) not allowed again until cleared by Tech.
  10. While division participants agree use of tire conditioning agents is difficult to police – all agree application of such will not be allowed at the track.
  11. Speedway management reserves the right to modify tire rules in conjunction with division needs & concerns.


  1. Car weights are race ready, full of fuel and with driver in the seat.
  2. Minimum total = 2750 lbs.
  3. Maximum left side weight is fifty seven percent (57%).
  4. An allowance shall be made for fuel consumption when weighed after the race.
  5. All ballast weight must be located outside of the driver compartment with each piece attached with a minimum of two (2) 3/8” bolts, washers and locking nuts.
  6. All weight must be lead with each piece painted white and display car number.


  1. Sealed Crate Engine……………-50 lbs.
  2. Cam Change Crate Engine……. -25 lbs.
  3. Muscle Car Body……………… -50 lbs.
  4. Dry Sump Systems……………..+25 lbs.
  5. Full Muscle Car Body………….-100 lbs.
  6. These weight breaks may be adjusted at any time by Wiscasset Speedway management in the interest of maintaining competition parity.


  1. All car numbers are assigned and registered by Wiscasset Speedway.
  2. When changing divisions, a new number will be assigned.
  3. Car numbers must be a minimum of eighteen (18) inches high and three (3) inches wide.
  4. Numbers shall be painted in contrasting colors to the car on both doors and the roof. Reflective chrome, gold or prism numbers will not be acceptable.
  5. Roof numbers should be visible as read from the grandstand side of the car.
  6. The car number must appear in six (6) inch high numbers in the uppermost corner of the windshield on the passenger side and also on the right rear.


  1. Two way communications shall be allowed; however, Wiscasset Speedway Management requires frequency registration.
  2. RaceCeivers are mandatory equipment.

All race car components, including sealed engines, may be subject to teardown/dismantle inspection at any time.   Refer to General Rules – Tech Information Section.

The definition of OEM for the purpose of rule interpretation is – a part specified by the manufacturer as being for a specific make, year, and model of an automobile or commonly available thru a replacement parts supplier such as NAPA, O’Reilly, Car Quest.  This does not include GM Bowtie or Ford SVO.

DISCLAIMER:  Motorsports At All Levels Pose A Risk To Your Well Being. Following The Rules Set Forth By Wiscasset Speedway In No Way Guarantees Or Suggests Your Safety.

Wiscasset Speedway Reserves The Right To Modify This Document At Any Time.  Such Modifications Will Become Effective And Enforced On The Next Race Date.

Last Edit 12/1/17

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