For whatever it is worth......

With factory stock model year 1995 specifications Magnum 5.9V8
the camshaft shows being installed 9 degrees retarded
by the Engine Analyser 3.2 software from Performance Trends.

At these factory specs
the engine is estimated to make at 2000 rpm full throttle
303 ft-lbs torque
0.531 BSFC

If the camshaft is advanced 4 degrees to 5 degrees retard
305 ft-lbs torque (slightly better)
0.532 BSFC (slightly worse)

If the camshaft is advanced further to 4 degrees advanced
307 ft-lbs torque
0.535 BSFC

Why would the low rpm torque improve at the same time that fuel economy gets worse?

The torque is probably improving because the intake valve is closing earlier after bottom dead center (advance) which improves 'dynamic compression ratio'

The fuel economy is probably getting worse because the exhaust valve is opening earlier before bottom dead center and the high pressure gas is pushing down on the piston for a slightly shorter time.

As an alternative mod to the valvetrain
consider reducing the rocker arm ratio from the stock 1.6
down to 1.3

Now at 2000 rpm full throttle you get

307 ft-lbs torque
0.526 BSFC

When an automaker claims that their addition of
"Variable valve timing with variable valve lift"
to an engine improves both fuel economy and low end torque
the above estimations show the benefit.

Some Americans claim to sell a mod to retro-fit this to V8s:

http://www.hotrocker.com/what.html

 

I will check this mod off my list of things to do becauseit is not worth my time for such a small gain.
Also not doing it eliminates the possibility of me breaking or damaging something! Doh![sm=smiley18.gif]
Thanks everyone for the info.