2019 THUNDER BOMBERS RULES
No nitrous or traction control
If driver refuses teardown 3 times, disqualified for remainder of year
Cars must be neat in appearance
Any driver in this division may compete in one other division on the same night
Car weight must be greater than 3300 lbs. after the race with driver
Cars must have numbers on sides and top readable by scorer
Stock unless otherwise noted.
Visual protest only.
No late model noses or tails.
Will remain stock unless otherwise stated.
1968 or newer American made car, no station wagons, trucks, jeeps, convertibles, mustangs, or pony cars.
Rear end of car must be closed, no holes or flaps or hinges.
Must have deck lid.
Front and rear fenders may be fabricated.
No side spoilers.
Rear spoiler may not exceed 60” wide by 6” tall with no spill plates.
Rear spoiler shall not exceed 48” from ground to top of spoiler.
Roof may be replaced if necessary but must be 48” x 50”.
Aluminum may be used for doors and fenders.
A minimum of 13” for all door and rear glass openings.
Interior may be boxed in.
Front and rear bumpers may be rubber like, stock appearing.
No holes in hood. If air cleaner is coming out of hood, it needs a hood scoop. Must be closed in front and sides, but can be open in back. Complete air breather must be covered.
May pull air from inside car, no forced air.
Front or rear inside wheel wells may be cut or removed.
All firewall holes must be covered.
Front firewall must be in stock original location, patching OK-add 50lbs if not stock
Must have stock floorpan. May patch.
Dash may be fabricated with steel or aluminum, but no higher than original.
Gutting trunk and hood ok.
Lexan ok for side and rear windows.
Bumper will not go past the inside of the rear tire.
Frame must match make and model of car, +/- 1”
Frame may not be shortened, stock only, no X braces or frame cutting
Length between spring eyes must be stock
The wheel base must be stock
Engine to remain in stock location
Radiator must be in stock location, may be Aluminum
Fuel cell must be inside of trunk with firewall between cell and driver
Seat must be securely fastened to frame and/or roll cage
Suspension must be stock unless noted
Racing spring with adjustable buckets OK
No adjustable lowering blocks, 4” max of fixed blocks
Top A frame may be may be tube type, non-adjustable, bolt in ball joints only on top A frame.
Heavy duty OEM steering and suspension parts OK
Leaf or coil springs may be changed to stronger of same type
Cutting coil springs OK, rear coil spring shims OK
Adjustable or non-adjustable spring buckets OK
Front shocks must be in stock location
Rear adjustable buckets ok
All chassis hook up points must be in stock location
Rear shock location must be stock on top but may be moved on bottom for travel length only
Can not change angle of rear shock
Top rear trailing arms may be cut for pinion angle only. No monoballs in any trailing arms.
Leaf spring perches and shackles may be reset for pinion angle
Aftermarket replacement bushings in A frames OK but no Heim Joints
Any stock body racing shock allowed, $125 buy rule per rear shock. $70 buy rule per front shock
No Heim Joints on any shocks.
WHEELS AND TIRES:
Steel wheels must be used, 8” wide, +/- .25”, 14 or 15 inch. Must be same all around
Tires may be any 70, 75, or 78 series street legal DOT tires
No directional or competition tires
TOWEL CITY recaps OK if 8” tread width, must punch 55 minimum after race
Bead locks OK right side only
Wheel spacers and offsets OK
Stock brakes for make and model
OEM calipers only
Dual master cylinder OK, Adjusters OK
No gun drilled or scalloped rotors
FLYWHEEL AND CLUTCH:
Stock steel flywheel, 14 lbs. min.
Stock type clutch and pressure plate, 10.5” minimum
Hydraulic or aftermarket throw out bearing OK
3/16” steel shield over bell housing required or blow proof bell housing mandatory.
Stock type automatic transmissions with working torque converter OK, 11” minimum
Transmission cooler OK . No power glides.
No lightening or polishing of any gears
Must have all working gears
Stock for make and model of car, 2” steel replacement OK
No carbon fiber or aluminum allowed
Safety Loop required around front of drive shaft
Stock type distributor ignition only
Stock firing order only
No high performance HEI, or distributors with external boxes
$150 buy rule minus plug wires.
May use GM 10 or 12 bolt, any gear
9 inch ford floater or non floater allowed
No gun drilled axles
No lightening or polishing of any parts
All components must be steel
Any OEM one or two piece seal block max 363 cubic inches assembled
Stock location only, aftermarket mounts OK
Approved repair parts only, must be approved
No flat top or 4 eyebrow pistons
Speed-Pro H423 or equivalent piston acceptable replacement for stock dished piston
ARP rod bolts ok if standard 3/8”
Stock cast replacement crankshafts OK
No knife edging or lightening allowed
Minimum crankshaft weight 48 lbs.
Stroke must remain stock
Stock rods with stock journals and pin diameters only
Aftermarket SFI balancer OK
Aluminum racing water pumps OK
Racing pulleys OK, no serpentine belts
Aftermarket fuel pumps OK
Any open chamber OK with following restrictions:
Stock production heads only
Aftermarket valve covers OK
Screw-in or pinned rocker screws OK. Screw in studs may not have hex heads. No guide plates.
Cannot be less than 72CC
No angle milling
Stock size of valve only for make and model, steel only
Z28 valve springs OK
No 3 angle or competition valve job, no cutting under 45 degree
Shims under springs maximum .060” under each spring
Stock rocker arms only, no long slot or roller rockers
Off set locks OK but no shims allowed
Stock valve stem only
No porting or polishing
Push Rods: Stock length and stock diameter required. Aftermarket and Hardened ARE allowed.
Headers: Any headers- No Tr-Y's or no crossovers.
Stock cast iron
No Holley pattern intakes
No aluminum intakes
Stock 2 or 4 Barrel
No modifications except may remove choke flap only
Box stock Holley 1850 OK with Mr. Gasket 1932 adaptor and 2 each .070 thick gaskets
Stock or Cloyes C-3023X timing chain only, no cam buttons
.390-.410 lift, 112 degree lobe separation, +/- 1 degree
Stock cam or Sealed Power CS-274, Melling CCS-2 or Comp 12-105-3 are approved
Hydraulic lifters only
Cam will produce 18” of vacuum at 1000 RPM
Amendment 11/9/18: There have been some interest in drivers wanting to run Ford's. However, there was no cam number in the rules. We have done some research and these are the cams that are equal to the Chevy.
Ford Elgin E750-S
Chrysler Elgin E577-S
PROTEST AND CLAIMS:
Bottom End $600
Any other three items $300
Acceptance Fee $100. Track keeps $100 for any protest above
$500 claim rule on Quadrajet.
Tech man has Final and indisputable say