Well I've learned way more this week than I ever wanted to know about valve stem seals (VSS). I finally called Trick Flow two days ago and they were great to talk to. I also felt better when they too were scratching their heads trying to find someone in the company that knew which seals came on 5.0L engines. Hey, they told me they make a spring kit (linked below) for the E7 head that requires no machining and that the kit includes new VSS. At least that gave me a starting point which allowed me to do more accurate searching and more importantly, finding! Oh, Trick Flow also offers the VSS only and that link is below as well.
So here's the simple answer. You can't look up the E7 head and just flop any seal on there. That's not how those seals are sold. That's why none of my searches using year, make,, model, etc was accurate or working at all. You must have 2 numbers period. Valve stem diameter and valve guide machined diameter. E7 heads from the factory have 11/32" valve stem diameter. The valve guide diameter is .555. That last measurement can change if your guides have been replaced and can only be found by measuring.
Next I grabbed one of my extra E7's which I should have done very first thing and pulled a valve spring off and look what I found.
That's a OEM valve stem seal that has never been off. It's only plain ole rubber. But it expels the myth that I've been told repeatedly this week (even by one Trick Flow guy at first) that the factory used umbrella seals on all E7 heads on the mustang. Good news if you ask me. Now I'm just hoping I don't pull my driver down and it doesn't have machined guides. Next pic...
There is the factory machined guide. As mentioned, it measured .555 with calipers. The VSS are double banded. This allows the lower metal band to stretch a bit with the rubber and then clamp back on the guide surface once installed. The upper band is much smaller but it only puts a firm seal on the valve stem to block oil. You can install these by hand with a drop of oil on the inside of the seal. Brand new ones and Viton seals might need installed with the help of a hammer and install tool or socket. Carefully till they click.
Now my next project since I've figured out what's what is to make a custom tool for taking springs off while on the car. Yes you can buy various store bought ones and I went thru about 4 different designs in CAD before I settled on this one. I like it because once it's cranked down your hands are free to remove the locks. Above I made two 4" studs from 5/16" all thread. I placed a washer under the nut on each and backed the stud out just a tad to keep it from potentially bottoming out when I tighten the tool down.
Here is the final paper template of the tool before I make it from steel. Even after deciding to make it like this I still went thru multiple templates before I was happy with it.
Another view of the template. I'm working on the steel version now and have it almost done. No pics of that yet but they will be coming soon. My goal in all this is to make spring removal in the car very simple and easy. I also don't want to be pulling on a bar trying to compress a spring and at the same time reaching with a magnet to grab the tiny locks that can disappear fast. I take lots of breaks now so a couple of sets and a break then back at it is the way I work.
One last thing for now on the seals is material. Viton is the best material currently in use unless some of the million-dollar supercars have some secret material discovered on Mars that they use. For us....Viton.
A word about Viton from wikipedia:
Viton is a brand of FKM, a synthetic rubber and fluoropolymer elastomer commonly used in O-rings, chemical-resistant gloves, and other molded or extruded goods. The name is a registered trademark of The Chemours Company.
Many thanks to the guys at Trick Flow for their help. I was at a stopping point until talking to them and figuring a few things out. Next up will be the finished valve spring removal tool.
Here are the links to the parts I found. I'm NOT buying the Trick Flow spring kit. I am buying their Viton VSS kit.
link to valve stem seals only:
https://www.trickflow.com/parts/tfs-2500100-vss
Summit Racing link for above:
https://www.summitracing.com/parts/tfs-2500100-vss/overview/
link to spring upgrade kit with all the specs:
https://www.trickflow.com/parts/tfs-2500100
Summit Racing link for above
https://www.summitracing.com/parts/tfs-2500100/overview/