I am rebuilding a 351w for my trail rig. I am more concerned with low end torque than I am with high rpm horspower. I bought a timing set that has keyway positions for 4 degree advance and 4 degree retard. It is my understanding that by advancing the cam timing I will create peak torque lower in the rpm band. Has anybody experiented with this? (on a 351w or other). Was there a noticible difference to low end torque? Is there a noticable effect to the top end performance?

If you shift you power down, you will have less on top. Shouldn't be a concern for a trail truck, unless you are running mud or sand where you can wind it up.

Yep. Put a double roller in my 302 advanced 4. Feels like more grunt down low, and it has no top end. It's just making noise above 4,000. (stock cam though)

I was planning on doing this in my 351w, but its a more then stock cam, about 216/228 @.050 duration.

Do you still line up the dots on the 2 gears or do you line up the dot on the cam gear and whatever the symbol is on the crank gear?

My set had a dot on the cam gear and a 3 keyway crank gear what had a dot, triangle, and rectangle for marks. The dot being straight up.

Go buy a degree wheel set and book. Dont guess at it

It doesn't have the keyway for a 0* setting? Factory retarded it for emissions, so putting it back to straight up will help in power all around. Not sure on if advancing it moves it down more though.

Don't advance the cam timing. You will lose a lot of mid range power. Run it straight up at 0* like it was intended.

Ford was known for retarding the cam timing to facilitate a leaner running engine at low RPM in the late 70's and 80's to get past EPA standards, but it utterly destroys the mileage and driveability.

Advancing the cam increases the cylinder pressure at low rpm by closing the intake valve earlier, increasing dynamic compression. This boosts low and midrange torque, but hurts cylinder filling at higher rpm.

Many mild aftermarket cams ( like Edelbrock Performer) are ground with the lobes advanced to the indexing pin so they are typically 4 degrees advanced with a straight up timing gear.

good explination, couldn't think of a good way to explain it like that.