I was changing my plug wires and notice that number #1 was in the back of the distributor cap. I was looking at a engine photo of a 352, and the number #1 was in the front of the distributor. The cap fits ok, and the truck runs ok, Is there a different distributor for that truck?, or is that correct?
Suggest rotate engine until #1 cylinder fires on the compression stock. BeIf you don't have a spark tester u can remove the plug and place finger in the plug opening and rotate engine until it forces finger out of the plug hole. It's just a rough indicator but will at least let u know if in the ball park. Also, check and see where timing marks are at. Posting pic, perhaps of some help.
The cap is mark #1 is right for number 1 plug, Just thought it was strange is was on the back if the distributor. Everything is in place, vacuum advance in front, etc. cap fits ok. Cap was notch to fit over screw on the vacuum advance, truck runs OK. I looked at a 352 engine on ebay (66 F100) and the #1 plug was in the front of the distributor. !!!!!!!!!!!!!!!!!! Anybody?
As long as the cap fits, wires connected according to their firing order, and timing marks line up it's good to go. Some caps are notched and can go on one way and the # 1 is a reference point. Not sure if the 352 cap can be rotated 180, but as long as spec's are within limits, and truck runs I would not worry about it.
It sounds like a previous owner simply did not pay attention to the #1 on the cap when he changed the wires, or cap, or even the entire distributor.
The engine doesn't care where the #1 on the cap is, as long as the #1 plug wire fires the #1 spark plug when the #1 cylinder is at TDC (give or take a few degrees).
Since the engine is running fine, I would leave it alone, unless you are comfortable removing and re-installing the distributor and resetting the timing and wires accordingly.
This type of work is relatively straightforward, but I would wait to do it until you can have someone present with you who is familiar with setting distributors and plug wire firing orders. This can become a nightmare because any one of a number of interacting factors can change the appropriate steps.
In other words, this is one job we may not be able to talk you through effectively, and you may end up with both time and money lost to pay someone to fix it.
This is one of those "if it aint broke, don't fix it" kind of deals, unless you really, really DO know what you are doing.
yea If aint broke ,don't fix it. You just don't know who worked on truck when you buy one. The thing that bug me was the number 1 was stamped on the back of the distributor cap and that was to the rear,and the advance is in the correct place. I just thought there was another distributor or I might have been looking at a 390. The engine was overhauled about 7yrs ago. The shop manual shows a little diffrent. Right now it is going to stay that way.