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A. All engines used in competition must be able to be used in conventional passenger

cars. Only the motors listed in rule book allowed. No Pontiac, Buick, Oldsmobile, AMC, or

other engines allowed. See section 1 general rules 1.1 general application. Castings and

fittings must not be changed. No machine work on outside of engine or on front or rear of

cam. No aftermarket blocks allowed. No Bowtie, SVO or any special production blocks

allowed. No splayed or aftermarket main caps allowed. No turning a block that was not

produced as a 4 bolt main into a 4 bolt main block. No grinding or polishing of any kind

allowed to the block. The two rear oil return holes in lifter galley can have the flashing

ground out of the hole only. Only the engines listed in the rule book allowed. No Pontiac,

Buick, Oldsmobile, AMC or other engines allowed. See section 1 General Rules, 1.1

General Application in the front of the rule book.

B. No total "dry sump" systems allowed. "Wet" system must be operative and will go

with engine if claimed. No external oil pumps of any kind allowed.

C. (1) single radiator only and must be mounted in front of engines.

D. Eligible engine CID and vehicle weight (minimum weight for all listed engines is 2600 lbs.):

Chevrolet 305, 307, & Ford 302 w/aluminum intake: (max. overbore .060")

Chrysler 318 w/aluminum intake: (maximum overbore .040")

Chevrolet 327, 350; Chrysler 340; Ford 351’s: (maximum overbore .060")

Chrysler 360: (maximum overbore .040")

No Chevrolet 302 engine components allowed.

Note: Reliable Chevrolet engine specs can be found online at: www.mortec.com

E. All engines must not exceed 9.5 to 1 compression ratio!!! No intermarriage of rods or

crankshafts to block allowed.

Example: 305 Chevy must run 305 rods & crankshaft

318 Chrysler must run 318 rods & crankshaft

350 Chevy must run 350 rods & crankshaft

351C Ford must run 351C rods & crankshaft

F. Crankshaft must be stock production (I.D. numbers intent). Stroke must match block.

No aftermarket or altered cranks. No lightening, grinding, knife edging or polishing of

any type allowed. Balancing allowed, material removal by drilling only. No heavy metal

allowed. No fluid balancers allowed (OEM balancers only). Balancer may be degreed but

must meet measurements specified below. No hubs only allowed. Minimum diameter 283-

307 and small journal 327, 6 1/8 x 3/4 inch thick. 305-350 and large journal 327 minimum

diameter 6 3/4 x 1 3/16 thick.

G. Connecting rods must be OEM stock steel production only. GM (OEM) powdered

metal rods allowed, must remain 5.7" length. No aftermarket rods allowed. Rod length

must match block. No grinding, polishing, sanding of rods allowed other than balancing

rod ends. Maximum 3/8" bolts. No cap screws. A minimum of 3/4 inch (1" recommended)

inspection hole in side of oil pan 2-1/2-inch down from pan rail in line with a journal.

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Inspection hole must be easily accessible to inspector; if not, the inspector may require

removal of oil pan. Floating wrist pins allowed.

H. Cylinder Heads must be stock cast iron production only. Any evidence of sanding,

polishing, relieving, grinding, porting, chemical treatment or addition of material

(chemical or otherwise) to the cylinder head ports or combustion chamber will cause

the head to be declared illegal. Cylinder heads multiple angle valve grinds permitted.

1987-1995 Chevrolet "Swirl port" heads allowed. Ford "302" GTP heads may be used

on both the 302 & 351W.

1. The following heads will NOT be allowed. No angle plug, bowtie, SVO, W-2,

Magnum, Vortex or any other aftermarket heads allowed at any time. Some of the

Chevrolet casting numbers NOT allowed include: 186, 187, 291, 414, 492, 461, 461X,

462, 432, 040, 041, 370, 10239906, 14011083, 14096217, 1012532, 10208890, or

12554290. No Gen. II heads allowed.

2. No external sanding, grinding or removal of ID numbers.

3. Any relief cuts made below the valve seat must be made using a carbide cutter

(no stones) and may not exceed more than 1/4-inch below the top of the valve seat.

No porting, polishing, grinding or port matching allowed at any time.

4. Stock production valve spring diameter only. No bee hive or tapered valve springs

allowed.

5. Screw-in studs & guide plates allowed. Pinning of press in studs allowed.

Valley pan allowed.

6. Stock type stamped steel rocker arms only; may have oil hole deburred. No roller

fulcrum or roller tip rocker arms.

7. No stud girdles allowed. Maximum valve sizes will not be specified. No polishing,

grinding, adding of foreign material or cutting allowed to combustion chamber.

I. Intake Manifold:

Chevrolet 305, 307 cid: Weiand #7547, 7546 or 7547-1 aluminum intake only.

Chrysler 318 cid: Weiand #7545 aluminum intake only.

(Note: The marketing division of Holley has replaced the Weiand brand name of some

products to Team G. Be certain that you refer to the product number instead. Additional

information can be found on the Holley website at www.holley.com.

Chevrolet 327, 350; Chrysler 340, 360; Ford 351 Cleveland and Windsor: only stock

O.E.M. two or four barrel cast iron unaltered manifolds only. No aftermarket, marine,

bowtie, SVO, W2 or any other special production intake manifolds. No throttle-body type

or fuel injection intake manifolds. No propane or Chevrolet raised plenum truck intakes

(casting number 14088674, 14088675) or similar intakes. May drill center intake bolt

holes to match 1987-1995 Chevrolet heads.

Ford 302: Weiand #7515 aluminum intake only.

J. Hydraulic cam and lifters only. No solid or roller cams and lifters. No bushing of lifter

bores allowed. Lifters must match block being used. No gear drives allowed. No coating,

painting or any other work to inside of intake manifolds, heads and block lifter galley

allowed. Lifters must collapse a minimum of .100”, be made of magnetic material and be

free to rotate.

K. Flat top or dished pistons only; no domed pistons.

L. Distributors. Stock O.E.M. distributors only. Billet distributors allowed. No multiple-spark

boxes. No magnetos or dual-point distributors allowed. Any coil used must fit in stock

cap and must use stock coil cover. Adaptacap allowed. GM H.E.I. Distributor can be

interchanged with Ford and Mopar engines.

M. May use aftermarket headers.

N. Engine Setback, Offset and Height: The rear of the engine must be mounted at least

72" forward from the centerline of rear axle. Engine offset must be kept within 2".

Engine height minimum will be 11".

O. Battery - (1) single 12 volt battery only. Dry or acid cell allowed.

48 © 2009 WISSOTA Promoters Association w i s s o t a . o r g 2 0 0 9

Battery must be securely mounted and shielded.

P. No crank trigger ignitions allowed.

Q. No vacuum pump/air pump allowed.

R. External cooling lines: maximum of 2 lines from the back of the intake to enter into

thermostat housing or spacer. No other external cooling lines allowed.

S. No piston type fuel pumps allowed. Must be stock diaphragm type.

T. Midwest Modifieds valve timing configuration and firing order must match the engine used

(example: Chevrolet 18436572)

U. All engines are allowed to run a valve train oil deflector.

V. No titanium engine parts allowed.

W. Main cap girdle not allowed. Crank scraper not allowed.

A. Carburetion will be limited to 1 stock Holley 500 CFM 2 Barrel, part #4412 with a

1-11/16" maximum throttle bore. No grinding or polishing of any kind allowed. All

carburetor components must be for a 500 Holley. No milling or grinding of throttle shaft

allowed, shaft must stay round. Choke and air horn may be removed, this is the only

re-working allowed on gasoline carburetors, all measurements must remain stock.

Carburetors using ethanol may make the necessary changes to the metering block etc.,

but can not make any alterations that increase the performance. No other changes

allowed, all measurements must remain stock!! No belt driven or electric fuel pumps

allowed. Must have mechanical type fuel pump mounted in OEM stock location.

Replacement high-volume fuel pumps allowed but must be mechanical type. Carburetor

must be mounted with float bowl forward.

B. Adapter Plate - Maximum thickness between carburetor and intake manifold with gaskets

and adapter will be one and three eighths (1-3/8) inches.

C. The promoter or any driver has the right to claim a carburetor from any car finishing the

feature race in the top four (4) positions for $125 or $25 and exchange. Add $75 if the

carburetor is converted to use ethanol.

D. Driver being claimed has the option of cash or exchange; promoter claim is cash only.

E. No driver may claim more than twice in one season. No driver can claim the same car

twice in one season.

F. Carburetor must have stock 4412 bodied carburetor only. No adjustable air bleeds. No

aftermarket or billet metering block allowed.