How high to drill the 7/8th hole?

Finally got the top of the keg cut. Now ready to install the weldless spigot. Specifically, I got this one:
http://morebeer.com/product.html?product_id=19807

For those of you that already did this and to save me the time from measuring it, how high did you make the hole from the bottom. As in the keg sitting on the floor and measuring up? I've heard 1.5 inches, but I really want to be sure.

I bought my keg already drilled out, but the fitting is, maybe an 1/8" above the where the bottom skirt and side wall are welded together. heres a pic you can just make out the weld, sorry i don't know the exact height. Yuri would know.

Cheers

https://cdn.homebrewtalk.com/gallery/showimage.php?i=2605&c=1&userid=7985

Grog,
at 1.5" your only into the retainer ring, assuming you have a Sanke style keg.
If I remember correctly, my was somewhere around 3 1/2" to 3 3/4" from the
bottom, and even then I was a little too close to the weld on the
retainer ring. I had to hammer that area down a bit so that the brass
locknut wouldn't bottom out on the weld.

Don't be afraid to go way up until you get onto the flatter surface. You'll use a dip tube anyway to get the last drop of wort out from the bottom concave anyway. You want the bulkhead to sit generally horizontal. I believe my dip tube has a 4" vertical drop down to the center of the keg.

Thanks. Yeah, it is a Sanke keg.

To make it exact, put everything together as if the hole already existed. Drop the false bottom and pickup tube into the keg, and mark where the pickup tube rests against the side of the keg with a permanent marker. This next part may take a little finesse...working inside the keg, use a small hammer and punch (or nail), to make a dimple on your mark. You should be able to see the dimple on the outside of the keg. Drill right next to it (not on top of it, the bit will walk all over).