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

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UPC:
00036584175278
Availability:
This part ships direct from the manufacturer, lead times, stock and shipping may vary.
Weight:
8.77 LBS
$298.18

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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 Flat Cam for Chevrolet Small Block

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

$298.18
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 Duration313
Advertised Intake Duration295
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 IncludedYes
Basic Operating RPM Range2,500-6,400
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 UpgradeCL12-602-4
Cam TypeHydraulic Flat Tappet
Cam, Lifter and Gear Drive UpgradeGK12-602-4
Camshaft Gear Attachment3-Bolt
Camshaft MaterialCast 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 Lift0.486
Grind Number295TH7
Intake Duration at .050 Inch Lift243
Intake Valve Lift0.5
K-Kit UpgradeK12-602-4
Lifter TypeHydraulic Flat Tappet
Lifters IncludedNo
Lobe Separation107
UsageStreet/Strip
Valve Springs RequiredYes

To submit a return or exchange request, please go to our Contact Us page to submit order information. Photos of any damaged products may be requested and required to process any full or partial refund. If approved, we will provide you with an RMA number along with a return label for shipping.

Parts returned that are not defective, are subject to a 25% restocking charge. JeepRecyclers.com/McDaniel Motor Co. is NOT responsible for any parts that have been altered, modified, disassembled, or damaged by misuse or an accident subsequent to the parts purchase.

Reconditioned parts come with a minimum warranty of 90 days, unless otherwise stated (Refer to product listing for warranty duration). The warranty is void if the parts are not returned in the same condition in which they are sold. Warranties for aftermarket parts are covered by the manufacturer.

What Are My Shipping Fees?

For orders delivered within the continental US where reason for return isn't a result of a JeepRecyclers.com/McDaniel Motor Co. error, the cost of the initial shipping charge and a return fee will be deducted from your refund. A prepaid shipping label(s) will be provided. The flat fee for each item being returned can be found in the chart below:

Retail cost of the item Per Item Return Fee
Less than $25.00 $3.75
From $25.00-$49.99 $5.75
From $50.00-$99.99 $7.75
More than $100.00 $9.75

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