I'm looking for a clear direction on paint markings. I understand there are model year changes etc that effected some of the marks. My car 6S1816 was built at Ford late March 1966 and left Shelby American 4/26/66. I have my front and rear springs done with the proper identification marks. All of the body assembly marks were photographed and duplicated back onto the car.
Rear housing and center section - lots (maybe 40) so will leave that for the moment
Steering linkage - Same as non-PS Mustangs. Center link at the drivers end/steering knuckle that attaches to the pittman arm. Applied with a brush and white paint it typically covers the knuckle from bottom outer edge to close to the boot and approx 3" wide
Steering box - Same as non-PS Mustangs with handling package. Only have a few examples of that specific box and not enough to establish a pattern at the moment. Don't use just one or two examples to establish a belief or standard for the markings
Idler arm mounting bracket - Short answer is that I would not add a paint mark at this time.
One or two forest green stripes applied with a somewhat narrow brush (approx 3/8") around the mounting bracket like found on Mustangs have been seen. This may only relate to a short section of the 66 production year and not to all 66's.
Idler arm - Short answer is that I would not add a paint mark at this time.
On the arm itself I've got non with a paint marking with yellow or any other color except for restored cars were the marking was likely borrowed from later (67-up) applications
Pittman- Short answer is that I would not add a paint mark at this time.
On the arm itself a few cars have been seen with yellow during the later half of production. Don't have enough examples to suggest this for all 66's. As a note 6 cylinders also use yellow marked arms but those were installed at San Jose where the Shelby ones were installed at SA. Because of this there was no need to color code these two items as they were for other items installed at the car assemble plant (San Jose in this case) though the supplier may have colored some for a while to identify them in their plants.
Tie rods - Would not apply any
Upper / lower control arms - Same as Mustangs. yellow on ball joint stud and a yellow band around the attachment shaft on the upper. Some paint would be knocked off the threads when the nuts were installed
Spindles - The major marks would be large yellow and pink paint on the steering arm section of the spindles. Both colors cover about 80 of the length and normally about 3/4 around the shaft (plus or minus a bit). Most spindles will have another four markings
Bonus for front suspension - Steering stops attached to the lower A arm. Both have a messy single pass of a brush on the flat middle surface on the concave side of the bracket/stop in strong red
Remember there is no reason to apply paint marks if you don't have 100% of the important details correct on the car. Nothing IMHO looks sillier than an incorrect part with a paint mark on it. If you worry or are considering having the car judges only the top classes require it and a incorrect marking will only cost you points. If you not worried about showing then do as you choose but remember others sill see what you apply and copying the details without asking questions or where you came up with them.
Hope this helps
Edited for a little more clarification