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

Free shipping on orders over $29.99

$560.95

$ 99 .00 $99.00

In Stock

1.:2,000-5,800 Rpm Range


2.Size:Cam And Lifter Kit


  • 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


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


Mary
2025-09-02 11:14:58
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.
Mike Troidl
2025-08-14 16:42:28
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!
Rick
2025-08-09 20:29:57
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
w earp
2025-07-16 17:16:32
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.
gobot02
2025-06-03 14:19:14
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.
Tyler Stroup
2025-05-09 15:29:51
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!
Josh S
2025-03-18 19:13:34
The media could not be loaded.
Customer
2025-03-12 15:53:16
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.
JCoulton
2025-02-20 16:20:15
The media could not be loaded.
G.b.a
2025-02-18 12:06:10
I’ve built many motors and broke in many cams and this is the fourth thumper cam that the lifters went flat I will not buy another comp cam product your just as well off to buy china lifters another engine garbage thanks comp cams
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