Cam swap on a stock 4.0L gives modest gain; on a stroker it's the difference between OK and great. Comp 232 is the safe choice, Hesco 274 is more aggressive.
The 4.0L stock cam is conservative: ~196° duration at .050, ~.430 lift. The two canonical aftermarket cams are:
Comp Cams 68-232-4: 204°/214° duration at .050, .460/.475 lift, 112° lobe sep. Idles smoothly, makes its torque broadly, pulls cleanly to 5000. Best all-around choice for a stroker with stock head. Works fine with the stock PCM tune.
Hesco H-274 (also sold as 'H-Cam'): 224°/224° at .050, .480/.480 lift, 108-112° lobe sep. Noticeably lumpy idle, more top-end. Wants a tune adjustment for the rougher idle and benefits from a port job on the head. Hesco also offers a 310° advertised duration cam with modified hydraulic lifters acting like solid lifters — only for serious builds.
On a stock 4.0L: a Comp 232 swap gains maybe 8-12 whp with proper break-in. Not worth doing as a standalone if the engine has good compression — you're inside it for a head gasket or stroker anyway. With a stroker block and matching components, the cam is worth 30+ hp.
Break-in is critical for flat-tappet cams. Use a high-zinc oil (Brad Penn, Driven HR1, or add ZDDP), prelube, run at 2000-2500 RPM for 20 minutes with no idling. Skipping break-in is the #1 way to wipe a lobe.
| Part | Vendor | Est. price |
|---|---|---|
| Comp Cams 68-232-4 kit | Comp Cams | ~$360 |
| Hesco H-274 cam kit | Hesco | ~$450 |
| High-zinc break-in oil 5qt | Driven | ~$65 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.