Does the SBF Dipstick tube have a seal where it enters the block?

[Rembrant]

I have another weird question...

So I bought this 1996 5.0 engine as a donor for my project, and unfortunately the original dipstick tube was rusted out. I snagged another one today from a junked truck...not sure what year, but a 90's F150 5.0. I know the tubes sit in the block the same on all of them...my 1984 302 was the same also, but I was curious...is there supposed to be a seal or an o-ring or something like that on the dipstick tube where it enters the engine block? I'm just wondering if there was a seal there at one time and it rotted away, or are they simply metal on metal from Ford?

[mat in tn]

so far i have not found one with a seal and most of the time i dont use one either but i have a time or two added a tight-fitting "O"ring no more than a 1/16' thick as long as the anchor point lines up well at the exhaust manifold.