Expect an increase of only 5HP by going from the stock 8.9:1 to 10.0:1....

CR Horsepower Change

You would get a much crisper throttle response, but the ECU would be somewhat helpful on ignition timing issues - particularly EGR equipped models. I don't know what the timing curves of other 3.0L engines are, but the '89 3.0L Federal model with base iginition timing set at 5 degrees BTDC runs ~ 40 degrees BTDC max under light load cruise (downhill) and is retarded to ~ 15 degrees BTDC under load/uphill/overdrive (no downshift) when all manifold vacuum is dumped around 2000 rpms.

IMO, for such a modest increase in HP, it's not worth the fuel cost of increasing CR unless other modifications are also made - like full head porting, larger intake valves, a different cam profile and an ignition timing controller - expensive, since it's mostly all custom work. A resulting change to low-end torque output from a different cam pattern would also be a question mark on driveability.

There are 2 reasonable answers for better all-round performance from the 3.0L in a truck - a blower or a stroker crank - both also expensive. IMO, anything less is probably a waste of time, effort and money.

Frank