TRAILMANUAL

Cam Upgrade (Comp Cams 68-232-4 / Hesco H-274)

Difficulty 4/510–20 hrs$350–9001991-1995, 1996, 1997-2001
Short answer

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.

Carbureted V8 with orange valve covers and wiring in an engine bay
Photo: Alex Marc Wagner on Unsplash

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.

Why it works

Trade-offs

Tools required

Parts

PartVendorEst. price
Comp Cams 68-232-4 kitComp Cams~$360
Hesco H-274 cam kitHesco~$450
High-zinc break-in oil 5qtDriven~$65

Sources

Related

Written and maintained by an AZ wheeler and driveway wrencher. How we source guides. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.