[V8] O2 Sensor replacement issues

[Unka Bart]

Gruss alles (I got the umlaut-delete option in my mail client, you'll 
have to supply your own)

Armed with the knowledge gleaned from you wise and handsome V8 mavens, 
I hied myself down to NAPA and got the sensor for a 93 ferd V8 F150 and 
out to replace the one on the Gentleman's express.  Promptly got stuck 
because I simply can't break the old one loose.  Tomorrow, I plan to 
take it down to a friendly shop I know and persuade the owner to put it 
on his rack and break the old sensor loose, letting me take it from 
there.

Question is, where on the block is the ground point that I can ground 
(the wire I will splice onto) the gray wire?  That is, how do I find 
that point?  Is there a screw terminal there, or what will I find and 
how will I know I have found it?

Second question is, does anyone know (and wish to share that knowledge) 
what gage wire I ought to purchase at my local FLAPS, probably NAPA, I 
should get in order to extend the gray wire to the ground point?

Direct responses cc'd to me would be greatly appreciated as I'm in 
digest mode.   But what the hell, helpful responses will be sincerely 
appreciated, however they arrive!

And Dave, learning to drive that (beautiful) motorhome (Congratulations 
again, mon cher ami) is about as difficult as remembering to check your 
mirrors and rear view monitor before changing direction.  IE, not 
difficult at all.  Scary as hell, the *first* time simply due to the 
size of the beastie, for sure.  But *difficult*, naw.  In fact, you in 
for a real treat.  You simply won't believe until you experience it how 
pleasurable it is to drive one cross country!

Short digression.  My first time ever behind the wheel anything larger 
than a pickup truck was in the (Converted ex-grayhound) GMC 4106 I was 
purchasing, in noon-rush traffic  in Houston along the "NASA" freeway, 
which was under construction/repair at the time.

There was a stoplight about every block and lanes defined by jersey 
barriers came and went about as often as the lights appeared.  With the 
Spicer non-synchro 4-speed manual  tranny, (which had to be 
double-clutched, matching engine and gear speeds *precisely*) that 
wasn't the most fun I've had in a motor vehicle by long shot, and I got 
a two hour dose of it (we were getting the 5.5 gallons of oil in the 
8V71 heated up for an oil-change).

The very next time I was behind the wheel was as I departed on my merry 
way to my first destination, Lake Charles, LA.  As an aside, I had 
developed a bit of diarrhea that morning, but by my noon departure, 
thought it was gone.  About 5 minutes after I cleared the Houston area 
and was rolling along I-10, I discovered that it wasn't gone.  You 
simply cannot imagine how wonderful it is to be able to pull over to 
the shoulder and use your own private facilities...

Yer kindly ol' Unka Whatizface