Street/strip, needs 9.5:1 compression, 2800+ stall, intake, gears and headers, very rough idle.
Designed to deliver an aggressive, hard-hitting exhaust note at idle, the Thumpr camshaft series from COMP Cams also delivers excellent horsepower gains and a broad torque curve. A perfect choice for muscle cars and street rods, the Thumpr series' early intake valve opening and long exhaust duration create optimum overlap for that race car idle. The Thumpr grinds all require an aftermarket torque converter and lower gear ratio to ensure the drivetrain always puts the engine in its powerband. Additionally, Thumpr camshafts typically deliver reduced vacuum at idle, making a vacuum canister, pump or hydroboost a requirement for vehicles running power brakes.

Application Summary:

Year Make/Model
1968-1974 American Motors Ambassador
1968 American Motors American
1968-1970 American Motors AMX
1978-1979 American Motors AMX
1966 American Motors Classic
1978-1979 American Motors Concord
1972-1976 American Motors Gremlin
1970-1977 American Motors Hornet
1968-1974 American Motors Javelin
1967 American Motors Marlin
1971-1978 American Motors Matador
1978-1979 American Motors Pacer
1969 American Motors Rambler
1968 American Motors Rebel
1970 American Motors Rebel
1966 American Motors Rogue
1979 American Motors Spirit
1974 Bricklin SV-1
1974 International 100
1974 International 200
1974-1983 Jeep Cherokee
1971-1981 Jeep CJ5
1971-1975 Jeep CJ6
1976-1981 Jeep CJ7
1972-1973 Jeep Commando
1984-1991 Jeep Grand Wagoneer
1971-1973 Jeep J-100
1970-1973 Jeep J-2500
1970-1973 Jeep J-2600
1970-1971 Jeep J-3800
1971-1973 Jeep J-4500
1971-1973 Jeep J-4600
1971-1973 Jeep J-4700
1971-1973 Jeep J-4800
1974-1988 Jeep J10
1974-1988 Jeep J20
1972-1983 Jeep Wagoneer
Attributes
Advertised Exhaust Duration 319, 319
Advertised Intake Duration 299, 299
Amazon ASIN N/A
ASIN B00N6LI03E
Assembly Lubricant Included No, No
Basic Operating RPM Range 2,500-6,400, 2,500-6,400
C.A.R.B. E.O. Number N/A
C.A.R.B. Exempt for Foreign Vehicles Manufactured Before 1967? Yes, but must meet tailpipe emission standards for year of vehicle.
C.A.R.B. Exempt for On-Road Vehicles? No
C.A.R.B. Exempt for Racing and Off-Road Only Vehicles? Yes, but must be a race/competition only vehicle.
C.A.R.B. Exemption Reason N/A
California Proposition 65 WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Cam Type Hydraulic Roller, Hydraulic Roller
Camshaft Gear Attachment 1-Bolt, 1-Bolt
Camshaft Material Billet Steel, Billet Steel
Camshaft Series Thumpr, Thumpr
Country of Origin (Primary) US
Emission Code Not in CA
Engine Family American Motors 290-401 c.i. 8 Cylinder (1966-1991), American Motors 290-401 c.i. 8 Cylinder (1966-1991)
Engine Make/Size AMC 290-401
Exh. Duration @ .050 in. (Deg) 257
Exh. Duration Advertised (Deg) 319
Exhaust Duration at .050 inch Lift 257, 257
Exhaust Valve Lift 0.537, 0.537
Exhaust Valve Lift (in.) 0.537
Grind Number 299THR7, 299THR7
Harmonized Tariff Code (Schedule B) 8409914000
Hazardous Material Code N
Int. Duration @ .050 in. (Deg) 243
Int. Duration Advertised (Deg) 299
Intake Duration at .050 Inch Lift 243, 243
Intake Valve Lift 0.552, 0.552
Intake Valve Lift (in.) 0.552
Life Cycle Status Code Available to Order
Lifter Style Hydraulic Roller
Lifter Type Hydraulic Roller Retrofit, Hydraulic Roller
Lifters Included No, No
Lobe Separation 107, 107
NAFTA Preference Criterion Code B
RPM Range 2500-6400
SDR Required Flag N
SDS Sheet Number N/A
Usage Street/Performance, Street/Performance
Valve Springs Required Yes, Yes
Warranty Time 12
GTIN 00036584266624

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