I recently bought a 69 f 250 camper special that's been sitting for three years . It has a 390 with C6 , did an oil change plus filter also transmission fluid and filter. didn't do a flush. It leaks at the valve covers , not bad but noticeable . Looks like previous owner put a new distributor on plus wires, have changed spark plugs. Also replaced the air filter.( don't know the name of it) air is being drawn directly over the motor because that one tube is missing on the cover. I am loosing a lot of power somewhere . take off is slow, uphill is a bad idea, and when all eight kick it lags. Had a guy mention the distributor , im thinking carb but im not sure. Truck reads 430,000 miles but cant imagine it be accurate. What can I do to bring a little more life to this classic? Also I have an annoying rattle coming from the front passenger somewhere in the suspension or steering. have found play in the tie rod but tightened in up . no more play. jacked it up tried jerking on suspension and steering assembly but found nothing . but I did find out the exhaust was modified. it lays on the chassis ,(opposite side to the second gas tank) bolted to the chassis with a welded piece of flat iron. Just want this rattle to stop, every little bump??????

 

Hey Josh, welcome to FTE!

You should start with first things first, the maintenance manuals recommend a compression test on page 1 typically. The idea there is, determine the basic mechanical engine health before wasting any time or money on anything. If the rings are totally shot a tuneup won't help, a new carb would be a waste, etc. if it tests OK, then a decision about how to proceed and further diagnostics, can be mapped out. Troubleshooting previous "repairs" can complicate things, as you've discovered.

Distributors and the plug wires can either or both be installed incorrectly and the motor will still run. Not very well. The timing can be way off on top of that too. Take the time to familiarize the proper firing order, how to find TDC and cylinder layout and such and make sure all that is correct. It makes troubleshooting and tuning a lot easier. There are a lot of smart people here who can help.

 

I guess ill start with the compression test

 

Welcome to FTE

What part are you calling the tube? The later trucks had a flexible accordion type hose that attached to the 9A626 snout, then routed to the radiator support.

But no 1968/72 F100/350 had any such thing.

 

Sounds like a plan - Charged battery, fully warmed up engine, all plugs removed, throttle open wide. Accuracy counts, take the time to do it correctly.

Don't be concerned so much the PSI # itself, what we hope to see is that they are all fairly even with each other. If compression is OK pick up a vacuum gauge, they are super useful for diagnostics and engine tuning. Spark plug condition is another window into the engine health - fouled or tan, fuel covered, oily? etc. With just a couple tools you can get a pretty accurate picture of the innards without too much work or tear down.

 

Everything Ted said is right. Report back with the compression check then someone can help diagnose your problem. Your rattle is probably the exhaust lying on the frame.