You'll gain a mile per gallon or two.

 

that will help this may sound dumb but do you have to have a full tank when you pour the seafoam in there. also how much in the tank and how much in the brake booster?

 

I've never done it myself. But I've listened to other people who have used the seafoam and they say it works very good. I used to put ATF fluid in a 409 spray bottle and spray it in the throttle body of my old ranger to do the same thing. That was a tip my uncle gave me, he worked for Ford. But I don't know how these trucks would react to that. Anywho, the directions on the seafoam bottle should tell you how much to use per gallon of gas. I'd use a full tank or at least 3/4 of a tank. Save a little when you pour it in your gas tank, then use the rest to pour down the brake booster line. You don't pour it directly into the brake booster... lol, you disconnect the brake booster vacuum line and pour it into the hose that leads to the upper intake manifold where the intake runners are located. The vacuum line coming from the brake booster will lead right to the intake manifold on the driver's side. Pour it slowly into the vacuum line a little at a time, or it will stall your engine. There will be lots of smoke coming from your exhaust while your doing this procedure with the brake booster vacuum line. It's nothing to worry about. That will help your pinging to stop. Sorry if my instructions are hard to understand. But I hope it works out for ya.

 

no i understand your directions perfectly and i want to thank you for all of your help. this is my first truck and i want it to last as long as it can. i bought it from a cousin and i know that it wasnt abused b/c his wife would only use it to go back and forth to work. if it can last as long as my dads i will be happy. he has a 95 f150 w/ a inline 6/5spd and he has 275,000 miles on it. the only thing that he has replaced is the clutch last year. so i hope to get atleast close to that.

 

You'll see alot of miles out of it if you take care of it and maintain it. And another thing...the 4.2V6 has a sound all it's own. Some people compare it to a deisel. Because it naturally sounds that way, some people think there's a problem. But there's not. Some say that the sound of the valvetrain is echoed or "amplified" by the huge intake runners. Which is what I think it is too. Mine has done it since day one. But it doesn't miss a beat. I thought you might want to know that, lol. Since this is your first truck. If you need anything just give me a yell and I'll try to help you out. GOOD LUCK WITH YOUR NEW FORD!

 

Why don't you do your own research (read up) on seafoam before using it? That specific information is abundant on this site. I have a 1990 f150 supercab xlt lariat with 105,500 miles that has been pinging since I bought it 4 months ago.
I tried seafoam twice. It might have helped. Dark smoke came out of the exhaut when I did it , so it might have cleaned some of the carbon deposit but most of the pinging is still there. I will be doing seafoam again soon when I am
1000 miles from my next oil change, using a variation on the basic method described above by Peacemaker. Let me explain. Here is how I will do it. I will buy three 12-oz cans of seamfoam from Advance auto ($5.85 / can). Then I will pour one can in the crankcase motor oil, making sure to not overfill. I will then drive the truck as usual, for about a month, that is about 1000 miles to let the seafoam treat the oil and loosen up deposits. In the second step, make sure to have about 1/4 full tank. After engine has been warmed up (the warner the better), in a well-ventilated area, stop the engine. Remove (pop off) the break booster vaccum line. Others have used the pcv valve hose as vaccuum. Pour about one and a half (18 oz ) of Seafoam IN A CONTAINER. Start the engine and working from the engine bay slowly suck the seafoam up in the intake by dipping the end of the brake booster line into the container, a few seconds a a time, while revving the throttle up to keep the engine from stalling. So you see, using this method, it would be hard to pour the seafoam directly in the vaccum line and do the other things at the same time. All this sucking will take less that a minute. Step 3: Stop the engine.Pour the remaining half (6 oz) of seafoam into the 1/4 tank of gas. Then wait 15 to 20 minutes to let the seafoam do its thing. Step 4: Start the engine up and burned up the 1/4 of gas. This is better done on a short smoke blowing trip on the highway. Step 5: Change your engine oil.
This is how I will do it the next time. The first time I used seafoam, the exciting part was blowing all that exhaust carbon smoke over that neighbors whole house and on the highway. There noticeably less black exhaust the second time around. Then as the truck is still somewhat loudly pinging on acceleration and under load, someone from this wonderfull site suggested that I keep the seafoam in the oil for a little longer (1000 miles) the next time.
Sorry for the long post. Hope that it will help.