Here guys hope this helps. It's not the easiest reading though.
OPEN 4X4
1. In order to qualify for this class, your vehicle must not exceed a wheelbase of 140”. No rear-engines allowed.
2. Open 4x4 vehicles are required to have a front and rear differential, both of which must be engaged at all times.
3. No belt drives allowed, Chain drive & transfer case only.
4. To qualify for this class, vehicles must show that front drive shaft will pull when rear drive shaft is removed.
5. Dual paddle tires are not allowed in this class.
6. Open 4x4 is a Pro Light Class required to run at least 175 feet. All spots will be figured @ 10 ft. per 1 spot.
7. Blown vehicles must have belt guards and blower hold down straps.
ENGINE MODIFICATION CHART
Performance Intake, one 4 barrel……………………………………..…½ spot
Sheet Metal Intake………………………………………………………………..1 spot
Any carburetor………………………………………………………………..…½ spot
Two 4 barrel carbs & intake……………………………………………….1 ½ spot
Two 4 barrel carbs with Sheet Metal Intake……………………………2 spots
All engines from factory w/performance pistons &/or cams must be claimed.
Cam change roller…………………………………………………………………1 spot
Cam change solid……………………………………………………………..½ spot
Piston change compression, weight, forged
or factory performance……………………………………………………….…1 spot
Fuel Injection……………………………………..………………………………2 spots
Fuel Injection-Electronic……………….………………………………..2 ½ spots
Turbo Charger 1 or 2…………..……………………………………………….5 spots
Blower……………………………..………………………………………………..5 spots
HEAD CHART
1. Factory Stock Production. Stock factory springs with factory pressure (2% pressure allowed). Stock valve job for that head, maximum valve
size: small-block 2.02, big-block 2.19. No roller rockers tip or
fulcrum………………………….………………………………………………………………………………………………………………………..…..…...0 spot
2. All of “0” spot with any size stainless steel valves and springs, roller rockers allowed. Three angle valve job aftermarket valve guides porting
(max depth ¼”) and .030 head resurfacing
allowed…………………………………………………………………………………..……………………………………………………………………..….½ spot
3. Any OEM cast iron head with any modifications allowed. No added or recast par……………..…………………….………..1 spot
4. Any aftermarket cast iron head OEM valve angle, port & polish…………………………………………………………….…....1 ½ spot
5. Any other cast iron head………………………………………………………………………………………………………..………….………..….2 spots
6. Aluminum stock factory (production head) with no modifications (Datsun,Toyota,etc.) 4 cylinder only…….… ½ spot
7. Any modifications to this type head will fall under cast iron head rules with the additional spots (not to include 1986 Corvette turbo head).
8. Any OEM aluminum head no port & polish, or no valve relocation………………………………………………………….……..…2 spots
9. Any aluminum aftermarket head ………………………………………………………………………………………….……….…………..2 ½ spots
FUEL
1. Racing fuel (octane booster added and non-pump type fuel or additive) must be under .770 specific gravity….…0 spot
2. Alcohol must be under .805 specific gravity………..……………………………………………………………………………………………1 spot
3. Exotic fuel-gas over .770 or alcohol over .820…….…………………………………………………………………………………..…….…3 spots
4. Nitrous Oxide,1 plate nitrous, gas solenoid…….………………………………………………………………………………………..……2 ½ spots
5. Nitrous Oxide,2 plates nitrous,1 gas solenoid…………………………………………………………………………………………………….3 spots
6. Top shot(additional spray bar), of nitrous to the top of the carb w/a nitrous plate at the base of the carb supplied by one nitrous solenoid is a
two plate system….……………………………………………………….…………………………………………………………….…….3 spots
7. Nitrous Port Injection, multiple systems……………………………………………………………………………………………………...3 ½ spots
8. V6’s up to 250 C.I. minus 20 feet (2 spots). Must be single carb, no nitrous, blower or turbo. When not claiming nitrous, you must
disconnect the line from the bottle(s) and it must be in plain view.
OPEN 4X4 CUBIC INCH SPOTTING CHART OPEN 4X4 WEIGHT CHART
C.I. Spot C.I. Spot
0……...100.……0 341…….375..…8
101…..130...…1 376…….420….9
131....170….…2 421…….450….10
171…..210.…..3 451…….480….11
211…..250……4 481…….580.…12
251…..275.….5 581……..UP....13
276..…310…..6
311…..340…...7
5901……..UP………….0
5801……5900………..½
5701……5800…………1
5601……5700……..1 ½
5501……5600………..2
5401……5500…….2 ½
5301……5400………..3
5201……5300…….3 ½
5101……5200………..4
5001……5100…….4 ½
4901……5000……….5
4801…….4900……5 ½
4701…….4800………6
4601……4700…….6 ½
4501……4600………7
4401…….4500……7 ½
4301….…4400……...8
4201…….4300…..8 ½
4101….…4200…..….9
4001……..4100…..9 ½
3901…….4000……..10
3801…….3900…..10 ½
3701……3800……11
3601…….3700…...11 ½
3501…….3600………12
3401…….3500…..12 ½
3301…….3400…..….13
3201…….3300…..13 ½
3101…….3200…..….14
3001…….3100…..14 ½
2901…….3000…..…15
2801…….2900….15 ½
2701…….2800……..16
2601…….2700….16 ½
2501…….2600…..…17
2401…….2500….17 ½
2301…….2400….…18
2201…….2300….18 ½
2101……..2200…….19
2001…….2100…..19 ½
1901……..2000……20
1801……..1900…20 ½
1701…….1800………21
1601……..1700…21 ½
1501……..1600…….22
1401……..1500….22 ½
1301……..1400…….23
OPEN 4X4
1. In order to qualify for this class, your vehicle must not exceed a wheelbase of 140”. No rear-engines allowed.
2. Open 4x4 vehicles are required to have a front and rear differential, both of which must be engaged at all times.
3. No belt drives allowed, Chain drive & transfer case only.
4. To qualify for this class, vehicles must show that front drive shaft will pull when rear drive shaft is removed.
5. Dual paddle tires are not allowed in this class.
6. Open 4x4 is a Pro Light Class required to run at least 175 feet. All spots will be figured @ 10 ft. per 1 spot.
7. Blown vehicles must have belt guards and blower hold down straps.
ENGINE MODIFICATION CHART
Performance Intake, one 4 barrel……………………………………..…½ spot
Sheet Metal Intake………………………………………………………………..1 spot
Any carburetor………………………………………………………………..…½ spot
Two 4 barrel carbs & intake……………………………………………….1 ½ spot
Two 4 barrel carbs with Sheet Metal Intake……………………………2 spots
All engines from factory w/performance pistons &/or cams must be claimed.
Cam change roller…………………………………………………………………1 spot
Cam change solid……………………………………………………………..½ spot
Piston change compression, weight, forged
or factory performance……………………………………………………….…1 spot
Fuel Injection……………………………………..………………………………2 spots
Fuel Injection-Electronic……………….………………………………..2 ½ spots
Turbo Charger 1 or 2…………..……………………………………………….5 spots
Blower……………………………..………………………………………………..5 spots
HEAD CHART
1. Factory Stock Production. Stock factory springs with factory pressure (2% pressure allowed). Stock valve job for that head, maximum valve
size: small-block 2.02, big-block 2.19. No roller rockers tip or
fulcrum………………………….………………………………………………………………………………………………………………………..…..…...0 spot
2. All of “0” spot with any size stainless steel valves and springs, roller rockers allowed. Three angle valve job aftermarket valve guides porting
(max depth ¼”) and .030 head resurfacing
allowed…………………………………………………………………………………..……………………………………………………………………..….½ spot
3. Any OEM cast iron head with any modifications allowed. No added or recast par……………..…………………….………..1 spot
4. Any aftermarket cast iron head OEM valve angle, port & polish…………………………………………………………….…....1 ½ spot
5. Any other cast iron head………………………………………………………………………………………………………..………….………..….2 spots
6. Aluminum stock factory (production head) with no modifications (Datsun,Toyota,etc.) 4 cylinder only…….… ½ spot
7. Any modifications to this type head will fall under cast iron head rules with the additional spots (not to include 1986 Corvette turbo head).
8. Any OEM aluminum head no port & polish, or no valve relocation………………………………………………………….……..…2 spots
9. Any aluminum aftermarket head ………………………………………………………………………………………….……….…………..2 ½ spots
FUEL
1. Racing fuel (octane booster added and non-pump type fuel or additive) must be under .770 specific gravity….…0 spot
2. Alcohol must be under .805 specific gravity………..……………………………………………………………………………………………1 spot
3. Exotic fuel-gas over .770 or alcohol over .820…….…………………………………………………………………………………..…….…3 spots
4. Nitrous Oxide,1 plate nitrous, gas solenoid…….………………………………………………………………………………………..……2 ½ spots
5. Nitrous Oxide,2 plates nitrous,1 gas solenoid…………………………………………………………………………………………………….3 spots
6. Top shot(additional spray bar), of nitrous to the top of the carb w/a nitrous plate at the base of the carb supplied by one nitrous solenoid is a
two plate system….……………………………………………………….…………………………………………………………….…….3 spots
7. Nitrous Port Injection, multiple systems……………………………………………………………………………………………………...3 ½ spots
8. V6’s up to 250 C.I. minus 20 feet (2 spots). Must be single carb, no nitrous, blower or turbo. When not claiming nitrous, you must
disconnect the line from the bottle(s) and it must be in plain view.
OPEN 4X4 CUBIC INCH SPOTTING CHART OPEN 4X4 WEIGHT CHART
C.I. Spot C.I. Spot
0……...100.……0 341…….375..…8
101…..130...…1 376…….420….9
131....170….…2 421…….450….10
171…..210.…..3 451…….480….11
211…..250……4 481…….580.…12
251…..275.….5 581……..UP....13
276..…310…..6
311…..340…...7
5901……..UP………….0
5801……5900………..½
5701……5800…………1
5601……5700……..1 ½
5501……5600………..2
5401……5500…….2 ½
5301……5400………..3
5201……5300…….3 ½
5101……5200………..4
5001……5100…….4 ½
4901……5000……….5
4801…….4900……5 ½
4701…….4800………6
4601……4700…….6 ½
4501……4600………7
4401…….4500……7 ½
4301….…4400……...8
4201…….4300…..8 ½
4101….…4200…..….9
4001……..4100…..9 ½
3901…….4000……..10
3801…….3900…..10 ½
3701……3800……11
3601…….3700…...11 ½
3501…….3600………12
3401…….3500…..12 ½
3301…….3400…..….13
3201…….3300…..13 ½
3101…….3200…..….14
3001…….3100…..14 ½
2901…….3000…..…15
2801…….2900….15 ½
2701…….2800……..16
2601…….2700….16 ½
2501…….2600…..…17
2401…….2500….17 ½
2301…….2400….…18
2201…….2300….18 ½
2101……..2200…….19
2001…….2100…..19 ½
1901……..2000……20
1801……..1900…20 ½
1701…….1800………21
1601……..1700…21 ½
1501……..1600…….22
1401……..1500….22 ½
1301……..1400…….23
