COMP Cams K10-600-5 Thumpr 227/241 Hydraulic Flat Tappet Camshaft K-Kit, AMC 290-401

The COMP Cams K10-600-5 packages the 227/241 Thumpr grind as a complete cam-and-lifter K-Kit for AMC 290 through 401 cubic-inch V8s. COMP's AMC/Jeep engine-family chart places this grind's coverage at engines built across three decades, 1966 to 1991.

Duration, lift and idle character

At .050-inch lift the spec sheet reads 227 degrees intake and 241 exhaust, with 279 and 296 degrees advertised and a 107-degree lobe separation. Intake valve lift comes in at 0.491 inch and exhaust at 0.476 inch. COMP puts the usable spread between 2,000 and 5,800 rpm and calls it a street/strip cam, with the choppy, thumping idle the Thumpr name promises rather than a smooth factory cadence.

Converter and gearing, and which kit you need

A stock torque converter will still move the car, but COMP recommends stepping up to a converter stalling 2,000 rpm or higher along with upgraded rear gears to put this cam's powerband to use. One detail worth checking before you buy: this same 227/241 grind is also sold by COMP under the CL10-600-5 part number as a plain cam-and-lifter set, without the K-Kit's extra hardware, so confirm which package your AMC build actually calls for.

What's included

As a K-Kit, this covers the camshaft and its matched hydraulic flat-tappet lifters in one purchase, aimed at AMC V8 owners building toward a street/strip combination rather than a quiet, stock-replacement idle.