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Big Mutha' Thumpr 243/257 Hydraulic Roller Cam for Chevrolet Small Block

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UPC:
00036584148401
Availability:
This part ships direct from the manufacturer, lead times, stock and shipping may vary.
Weight:
8.77 LBS
$557.63

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A Portion Of The Proceeds From Your Purchase Supports The Development & Reproduction Of High Quality 1963-1991 Restoration Parts.

Big Mutha' Thumpr 243/257 Hydraulic Roller Cam for Chevrolet Small Block

Big Mutha' Thumpr 243/257 Hydraulic Roller Cam for Chevrolet Small Block

$557.63
Street/strip, needs 9.5:1 compression, 2800+ stall, intake, gears and headers, very rough idle.

Installation Instructions

Installation Instructions



This Part Fits:

YearMakeModelSubmodel
1968-1971JeepJ-100Base
1969-1971JeepJ-2500Base
1969-1971JeepJ-2600Base
1969-1970JeepJ-2700Base
1969-1970JeepJ-3500Base
1969-1970JeepJ-3600Base
1969-1970JeepJ-3700Base
1969-1971JeepJ-3800Base
1968-1971JeepWagoneerBase


Advertised Exhaust Duration319
Advertised Intake Duration299
ApplicationsFits Chevrolet GEN 1 Small Blocks including the 262, 265, 267, 283, 302, 305, 307, 327, 350 and 400. Does not fit LT1/LT4, or factory roller Small Blocks built from 1985 and newer. GM gradually added roller camshafts to 305's and 350's from the mid 80's forward. Camaros/Firebirds/Corvettes received the roller cams early, but many trucks and SUV's had flat tappet cams until the mid 90's. Remove the intake or timing cover to confirm whether the block is a factory roller or flat tappet. Does not fit the LS1, LS2, LS3 or any LS-based 4.8, 5.3, 5.7, 6.0 and 6.2. 1955-1957 Chevrolet 265 engines require a groove on the 5th cam journal for oiling. Contact us for more information.
Assembly Lubricant IncludedNo
Basic Operating RPM Range2,500-6,200
C.A.R.B. E.O. NumberN/A
C.A.R.B. Exempt for California Certified Vehicles Manufactured Before 1965?Yes, but must meet tailpipe emission standards for year of vehicle.
C.A.R.B. Exempt for Federally Certified Vehicles Manufactured Before 1967?Yes, but must meet tailpipe emission standards for year of vehicle.
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 ReasonN/A
California Proposition 65WARNING: Cancer and Reproductive Harm P65Warnings.ca.gov
Cam and Lifter Kit UpgradeCL12-602-8
Cam TypeHydraulic Roller
Cam, Lifter and Gear Drive UpgradeGK12-602-8
Camshaft Gear Attachment3-Bolt
Camshaft MaterialAustempered Ductile Iron
Camshaft SeriesThumpr
DescriptionStreet/strip, needs 9.5:1 compression, 2800+ stall, intake, gears and headers, very rough idle.
Engine FamilyChevrolet 262-400 c.i. 8 Cylinder (1958-1998)
Exhaust Duration at .050 inch Lift257
Exhaust Valve Lift0.517
Grind Number299THR7
Intake Duration at .050 Inch Lift243
Intake Valve Lift0.531
K-Kit UpgradeK12-602-8
Lifter TypeHydraulic Roller
Lifters IncludedNo
Lobe Separation107
UsageStreet/Strip
Valve Springs RequiredYes
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