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Comp Cams

COMP Cams K12-601-4 Mutha' Thumpr 235/249 Hydraulic Flat Cam K-Kit for Chevrolet Small Block

    • Based on 234 reviews
Condition: New
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Availability: Only 1 left in stock, order soon!
Fulfilled by Amazon
Arrives Tuesday, Feb 25
Order within 13 hours and 12 minutes
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Size: K-Kit


Style: 2,200-6,100 RPM Range


Features

  • High performance street/strip, needs 9:1 compression, 2500+ stall, intake, gears and headers, rough idle.
  • 2,200-6,100 RPM Operating Range
  • 235/249 Duration at .050". 107 Degree Lobe Separation Angle. 0.489"/0.476" Valve Lift
  • K Kits vary in their contents, but generally contain a camshaft, a set of lifters, valve springs, retainers, locks, valve seals, timing set, assembly lubricant, decals and instructions. Check description for more accurate listing of kit contents.
  • Early intake valve opening and long exhaust duration create optimum overlap for powerful, hard-hitting exhaust note. Best with aftermarket converters and more rear gear.
  • Perfect choice for muscle cars and street rods - Three unique cam designs: Thumpr, Mutha' Thumpr and Big Mutha' Thumpr deliver excellent horsepower gains and broad torque curve.
  • Fits 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.
  • Made in USA

Description

High performance street/strip, needs 9:1 compression, 2500+ stall, intake, gears and headers, rough idle. K12-601-4 contains the following: 12-601-4 Mutha' Thumpr 235/249 Hydraulic Flat Cam for Chevrolet Small Block, 812-16 High Energy Hydraulic Flat Lifter Set for Chevrolet Small and Big Block., 2100 Magnum Double Row Timing Set for '78-'86 Chevrolet V6 and 265-400 Small Block, 981-16 Set of 16 Single Springs w/ 1.254" O.D., 1.254" I.D., 1.700" Installed Height, 601-16 Hardened Steel Set of 16 - 7 Degree, 11/32", Single Groove Street Locks, 742-16 7 Degree Steel Retainer Set of 16 for SBC, Chevrolet/Buick V6 w/ 1.250" OD Spring, 501-16 Set of 16 O-Ring Valve Seals for Stock Guide Size, 11/32" Valve Stem

Manufacturer: ‎COMP Cams


Brand: ‎Comp Cams


Item Weight: ‎21.2 pounds


Product Dimensions: ‎26 x 10.5 x 5 inches


Country of Origin: ‎USA


Item model number: ‎K12-601-4


Manufacturer Part Number: ‎K12-601-4


OEM Part Number: ‎N


Date First Available: February 9, 2009


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Feb 25

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

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Top Amazon Reviews

    • Very happy with this cam....
Size: Cam and Lifter Kit Style: 2,200-6,100 RPM Range
Comp cams are the best. I have a very long story here. I will try to keep it short, but what I have to say may be helpful. Originally I purchased the Performer RPM package. I researched everything and was told by few that the RPM cam was the best choice because it has been dyno matched with the heads and intake. I ran the RPM cam and lifters and I was very disappointed with the results. THEN, I heard my rockers ticking as if they were loose. After proper cam break in of cam lube and high zinc break in oil, the RPM cam rounded out 2 lobes and about 4 lifters were damaged. In my experience, the RPM cam and lifters are crap. I purchased the Comp Cam and the power difference was very noticeable, the sound was more aggressive, and the throttle response was more snappy. I'm VERY happy with this cam. ... show more
Reviewed in the United States on December 31, 2018 by Mary
    • Customer Service
Size: Cam and Lifter Kit Style: 2,500-6,400 RPM Range
Outstanding customer service. I returned an item that I mistakenly ordered the wrong cam. I called and they were very nice and professional. I followed up a couple days later and talked with a different young lady and received the sane high quality service. The return was simple and painless. Product was perfect and as advertised. I will definitely be buying products from them in the future! ... show more
Reviewed in the United States on March 16, 2024 by Mike Troidl
    • Competition Cam Review
Size: Camshaft Only Style: 2,200-6,100 RPM Range
This is a well designed cam for a Great sounding hot rod.However, it will not work in stroker motors due to intereference with the crank shaft.Stroker motors must use cams cut on a small base circle.I had to return the cam for this reason.I didnt know when I purchased the cam that it was not cut on the small base circle as the cams I had installed in this motor in the past WERE cut on that small base circle and had given me no problems at all.I'm sure it would work well in standard 400's and 350's as well as other small block chevys with original crank shafts,(non stroker motors).Sincerely,Handy7rick at yahoo.com ... show more
Reviewed in the United States on September 3, 2012 by Rick
    • Great sound!
Size: K-Kit Style: 2,000-5,800 RPM Range
Great price and sounds great. Everything is there except for spring cups that go under the springs. You may not need them, depending on your setup, but just keep that in mind. Timing chain isn't a true roller, but that may not be such a big deal. Break in lube is included in a plastic packet, which I missed. I used my own moly based cam lube. Put some ZDDP in your oil and do so at every oil change. ... show more
Reviewed in the United States on July 14, 2015 by w earp
    • Has a very gnarly muscle car lope now and I love it! All parts were within specs and accurately ...
Size: K-Kit Style: 2,000-5,800 RPM Range
Quality cam as expected from Comp! Has a very gnarly muscle car lope now and I love it! All parts were within specs and accurately machined! Very satisfied with my purchase!
Reviewed in the United States on April 5, 2018 by Tyler Stroup
    • I love this camshaft!!!
Size: K-Kit Style: 2,000-5,800 RPM Range
Great camshaft I love the sound and performance. in my opinion the recommended stall converter for this set up is a little to conservative. you need to put a 2800 stall or higher torque converter on to run this cam on a street car.
Reviewed in the United States on November 5, 2018 by gobot02
    • Cam will not work with a stroked small block Chevy
Size: Cam and Lifter Kit Style: 2,200-6,100 RPM Range
There was no mention as to the fit with a stroked small block Chevy. Be advised that if you are running a stroke longer that 3.75" that you will need to clearance your rods to avoid cam lobe contact or return this camshaft. You need a small base circle if you don't want to clearance your rods. THIS CAM WILL NOT WORK and it should be noted in the description, but is not. ... show more
Reviewed in the United States on January 22, 2024 by Amazon Customer
    • good stuff
Size: Camshaft Only Style: 2,000-5,800 RPM Range
The media could not be loaded. if you are looking for a cam that makes your engine sound meaner than it is. this is the one for you. all the headaches of a big cam without massive power gains. Its just what i wanted so i loved it. i daily drove a truck with this cam for a year gettin around 8mpg. every time you start it you'll forget all about all the money you pay at the pump ... show more
Reviewed in the United States on January 17, 2020 by Josh S

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