With a stock tune the amount of timing is rather small, once you start getting into bigger lower pulleys, and smaller upper pulleys the amount of timing is very critical, espically if its your daily driver the more timing the greater the fuel you need9 i.e. (sunoco 104 octane, 116 octane) to counter the amount of fuel being burned.

Most people get a single flash chip and run that all the time, most tune these with more timing for summer temps. but in the cold that could cause you to be looking into a new motor if you encounter detonation.

Also the amount of boost your running at those speeds with the sudden vac pressure is not good.

These trucks are made for stop light to stop light, it is really hard to make these bricks good highway monsters. plus the rods are extremly weak, and earlier model L's are known for throwing plugs. Have fun and be safe

For more indepth info do a search on these Lightning sites where it has been discussed hundreds of times

http://www.TALONClub.com

http://www.NLOC.net

http://www.f150online.com/forums/forumdisplay.php?f=50