1. Buy a tape measure

2. Crawl under the truck

3. Measure the distance from the headers to the ground.

4. The measurement is how far you can lower the truck.

5. If you want to drive it instead of just letting it sit around at car shows, it might be a good idea to leave a couple of inches of clearance so it will only drag the pipes when you hit a bump.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!