Partial Mash BCB Robust Porter issue...

So, I wanted to try a porter recipe with my new 5-gal stock pot. I decided I wanted to do a full boil, Partial Mash recipe. So I started out with EdWort's Bee Cave Brewery Robust Porter...

https://www.homebrewtalk.com/f126/all-grain-bee-cave-brewery-robust-porter-56768/

However, to scale it down to a 4 gallon wort and a partial mash recipe, I came out with the following ingredient list...

5# Rahr 2-row
3# Light DME
12oz. Chocolate
12oz. Crystal 40L
3oz. Black Patent
<1oz. Roasted Barley
6oz. Flaked Barley

0.75oz. Northern Brewer @ 60 min
0.75oz. Cascade @ 60 min
6oz. MaltoDextrin @ 20 min
1t Irish Moss @ 15 min

WLP002 Yeast - No starter

Alright, mash in with 8.5 quarts (q) of 165F water, added grain and into the oven at 150 for 60 min. Dunk sparge with 8q at 178F for 10 min, then did a "pour over" with a colander into my 8.5q of wort for a total of about 16q of liquor, then I topped off to 19q for the boil.

Took about 20 min to bring this to a boil (stovetop w/ a 16,500 btu burner), then boiled following the recipe above. Cooled and took a hydrometer sample before pitching. The hydrometer sample was still at about 80F when I pitched (using a swamp cooler, so I'm confident the high temp won't stay high), so I didn't get my OG until about an hour later (forgot about it during the cleaning)...

OG - 1.084 @ 60F

Wow, wasn't expecting that. Well, it'll be interesting to see how it turns out. Can someone double-check my numbers to see if I should be getting an OG that high? Using the Beer Recipator (below), I get an OG of 1.081 (assumed efficiency at 70%)

http://hbd.org/cgi-bin/recipator/recipator