[larrymur1961]

Action
This is the configuration, even though "1" is not at 12 o clock. It looks like it's rotated clockwise. The clips being located between 1 and 5....and 6 and 3. So the clips located are slightly different to diagram. I checked all the cables going from the distributor and they are all correct. I placed white numbers on the cables so you could see, however the numbers are also on the cables themselves.
What do you think?

 

[ms fowler]

"Lets say the spark plugs are in the correct position..."
STOP right there---solve one thing at a time. Make absolutely sure that the WIRES are in the correct position. Do not adjust anything else or move to another potential problem until you KNOW the wires are right.
Way too many people just start replacing this, and moving that, and adjusting this---and all of of sudden nothing works.
Be systematic and thorough.
Also--I "assume" the spark plugs are in the correct locations--I mean they only go one place--in the cylinder head by the exhaust manifold. I think we are discussing the spark plug WIRES--not the actual plugs. Remember that Ford does not number its cylinders the same way that Chevy does. Make sure you are using Ford information from the correct year. I If the plug wires are old and cracked, they should be replaced. It would be helpful if ypou could post a picture of the wires that the mechanic say "do not fit". I would start with the distributor cap. Put it on the distributor ( make sure the rotor is on top of the shaft first and that it is locked in its position.) The cap only fits one way--that notch will prevent you from putting it one wrong. Once the cap is on the distributor. hook the spring clips (2)--one on each side that hold the cap on the distributor. Then run the a spark plug wire from terminal 1 on the distributor to spark plug number one. Then--working in the firing order, and GOING IN THE CORRECT DIRECTION install one spark plug wire at a time. When done all 8, make sure that none are touching the exhaust manifold or they will burn and short out and you engine won't run smoothly.
The Shop Manual would probably have a picture showing how the factory routed the wires. That might be helpful.
Good luck....that 390 should run very smoothly.

 

[ms fowler]

I did not see Action's pictures before i posted. Look carefully at them and make yours look the same.

 

[Action]

Spark plugs are all the same. They can go in any hole.

The cables are critical.
The cables that are easiest to mix up are ones that are next to each other in the firing order.
Like 7 and 8
Which makes tracing the cables important.
Start with #1 and trace the cable from the cap to the #1 spark plug.
Move to the next in order. #5 Trace from the cap to the #5 spark plug.

Do that for all cables and the issue will be detected.

Action

 

[Action]

The cables that are numbered are reproduction. And rather expensive.
Same for the coil.
Kudos!!!

Action

 

[redrag]

notice that the wires are not in FE firing order

 

[ms fowler]

notice that the wires are not in FE firing order

Good catch

 

[larrymur1961]

I did not see Action's pictures before i posted. Look carefully at them and make yours look the same.

I agree 100% what you say, I don't have a manual yet, ordered one. On the photos "1" is not in the 12 o clock position but the clips on my car are different from the link below. My clips are between "1-5", and "6-3".
Redrag... are you saying that the wires are not in correct FE firing order, since "1" is not at 12o clock? Also is a picture of the new cables I purchased

 

[larrymur1961]

I did not see Action's pictures before i posted. Look carefully at them and make yours look the same.

I agree 100% what you say, I don't have a manual yet, ordered one. On the photos "1" is not in the 12 o clock position but the clips are different from the link below

 

[larrymur1961]

I did not see Action's pictures before i posted. Look carefully at them and make yours look the same.

I agree 100% what you say, I don't have a manual yet, ordered one. On the photos "1" is not in the 12 o clock position but the clips are different from the link below

 

[larrymur1961]

I agree 100% what you say, I don't have a manual yet, ordered one. On the photos "1" is not in the 12 o clock position but the clips are different from the link below

spark plugs wires from Rock auto. 7807

 

[larrymur1961]

I did not see Action's pictures before i posted. Look carefully at them and make yours look the same.

I agree 100% what you say, I don't have a manual yet, ordered one. On the photos "1" is not in the 12 o clock position but the clips are different from the link below

 

[redrag]

sorry. your order is correct. you can have #1 anywhere on the cap as long as the order is correct, and #1 is where tdc #1 lines up on the cap. if it's a points system, make sure the dwell is ok and i would just put in a new condenser

 

[LarryM1961]

Thanks Re-drag, Even though the mechanic said Spark Plug leads looked ok, but its always good to change them I suppose, not sure if he checked the resistance? Perhaps the Spark Plugs themselves? Not sure where to go from here, order is correct. These are the old Spark plugs and the box with the new which supposed to fit a Ford Galaxie 500 from Rockauto as the spark plug cables are supposed to.

 

[LarryM1961]

Thanks Re-drag, Even though the mechanic said Spark Plug leads looked ok, but its always good to change them I suppose, not sure if he checked the resistance? Perhaps the Spark Plugs themselves? Not sure where to go from here, order is correct. These are the old Spark plugs and the box with the new which supposed to fit a Ford Galaxie 500 from Rockauto as the spark plug cables are supposed to.

 

[LarryM1961]

Action, Re-drag and Ms Fowler,
I think perhaps I should put the old spark plugs back in. Not sure in car auto repairs, but in IT, if one makes a change and doesn't work, we roll back, since that was the only thing that was changed and maybe the spark plug leads were distrubed, but are in they are in the right firing FE order. What do you think? Thnx larry M

 

[Action]

Check base ignition timing first.
If you do no have a timing light, your mechanic should be able to do that

Action

 

[redrag]

timing and sparkplugs don't cause backfire. ignition randomly shutting off does. ign switch, wires to coil and distributer, points and condenser

 

[LarryM1961]

timing and sparkplugs don't cause backfire. ignition randomly shutting off does. ign switch, wires to coil and distributer, points and condenser

Thanks Action/Re-drag,
I;m going to change the Spark Plug wires, however, the mechanic did say that there was leak from the mainfold to the exhaust, which probably caused the Pop backfire. However, since this change with the spark Plugs and not replacing the spark plugs leads it's backfiring like a .357 Magnum now opposed to a "pop" before.
I'll get the mechanic to check the timing
Thanks
Larry

 

[ms fowler]

I see no reason why those wires will not work. They look like replacements for the original and should fit right in the cap and on the plug.

By the way, what part of the country are you located?