Late Model Rules
Cast iron only. 362 cubic inch max
Steel, GM 23 degree - Ford 10 degree
Any steel crank.
No titanium or aluminum rods.
Any flat top pistons and pins. Zero deck. Plus or
minus .003 tolerance
Max intake 2.055, max exhaust 1.600. Titanium permitted.
Any one (1) four barrel permitted. GAS
Any point or electronic ignition. NO traction control.
All boxes subject to removal for inspection.
¤ Fronts - Open Rears - Hoosier D55, 1600
or American Racer 56. Rears must durometer minimum
Lucas body rules. All cars must have windshield
OTHER THAN STOCK STROKE – ADD 50LBS DRY SUMP – ADD 50LBS
49.5LB MINIMUM CRANKS - MAY DEDUCT 50LBS
**Weight must be posted on right-side A-pillar.
Failure to post correct weight will result in disqualification.
One(1) Head & Bore: $400, Bottom End: $400, Complete: $600 -TRACK
Retains 30% - Visual $50
Any driver who refuses to tear down will be
considered illegal and be required to start at the
rear of the next feature event.
Any car found illegal during qualifications
will be required to start at the rear.
CRATE MOTOR Option
or Rebuilt 604 Crate - 2300lbs
In an effort to maintain equal
competition and parity among engine combinations,
starting Saturday, May 12, Crate motor Late Models
may run the 32X12" sideboard with an 8"
spoiler OR a 12" spoiler with standard triangular
side panels. You man not run the sideboard with
a 12" spoiler. Either/or.
Fronts - Open Rears - Hoosier D55, 1600 or American
Racer 56. Rears must durometer minimum 50, anytime
must use following factory spec GM parts:
1. GM Block: #10105123
2. GM Crank: #14096036 Minimum weight 54lbs. No
alteration of stroke, rod, or main journal diameter.
3. GM Rods: #12495071 - Must use GM rod bolts
4. GM Cam: #10185071
5. GM Cylinder Head: #12497186
6. GM Head Bolts: #12495499
7. GM Intake Valve: #12555331
8. GM Exhaust Valve: #12551313
9. GM Push Rod: #12371041
10. GM Rocker Arm and adjuster nut: #12367345
11. GM Rocker Stud: #12371058
12. GM Lifters: #523890
13. GM Spider and Lifter alignment
14. GM Intake Manifold: #12496822 (UNTOUCHED)
15. GM Balancer: 12555879
following Repair and Rebuild parts will be allowed
for Crate Option
1. Oil Pan - Champ Pans Part #CP100LTRB
2. Oil Pump - Standard
Cast Iron SB High Volume Pump
3. Piston - Mahle
Part #027520 - Max Overbore .030 - Must use supplied
wrist pin. No other alterations other than balancing.
4. Rings - May use Hastings, TRW, Sealed Power.
No gapless rings.
5. Gaskets - Any gasket. Head gaskets must be same
compressed thickness as factory GM Part #12557236
gasket which is .051.
6. Valve Springs - Aftermarket valve springs and
seals are allowed, but must use factory retainers
7. Bearings - May use aftermarket engine bearings.
No rollerized bearings.
8. Timing Chain & Gear - Cloyes
9. Seal bolts not required.
Machine Work for Option #2:
Rotating assembly may be balanced. Crankshaft balancing
may only be done by drilling or adding weight to
counter-balance. No narrowing or knife-edging of
crank will be permitted. No aftermarket sleeves
allowed. Minimum piston deck height
.010. No angle milling. May be line honed.
No polishing of the block. Excessive casting debris
may be removed. No performance enhancing coatings.
Surfacing of the head for repair is permitted. No
angle milling. Multi-angle valve job with minimum
44 degree and maximum 46 degree for primary valve
or seat angle permitted. Combustion chamber cannot
exceed 58cc minimum. Intake port
210cc max. Exhaust port 82cc max. Compression
Ration maximum of 10.0:1.
#2 Disclaimer: The 604 rebuilt Crate
Option #2 is intended to allow a racer a chance
to rebuild or repair the GM 604 Crate. Nothing in
these rules and guidelines are designed to improve
the performance of the GM 604, only give the racer
a low-cost alternative to Crate Option #1. Rebuild
kits are available from Motor Warehouse in Sacramento,
CA by calling 1-800-367-6717,
and Part #PCH350D available with, or without pistons.