I'm not related to this Gross/Groce family, but looking at some of the names I wrote down from the 1880 MO Soundex, there is a Pleasant Groce age 62 born in KY listed in Howell County, MO [15-51-34-25].
Going through some of my other notes, I find:http://members.fortunecity.com/shariben/docs/census/censusky...
1860 Clinton County, KY Census
Groce, Pleasant 42 M farmer KY
Groce, Martha 39 F housework TN
Groce, Sarah E 18 F domestic KY
Groce, James 17 M domestic KY
Groce, Victoria E 15 F domestic KY
Groce, Richard V 11 M KY
Groce, Willis M 9 M KY
Groce, Robert H 7 M KY
Groce, Mahala H 5 F KY
Groce, Vienna J 1 F KY
1850 Clinton County, KY Census
Gross, Pleasant 32 M farmer KY
Gross, Martha 28 F KY
Gross, Sarah E 8 F KY
Gross, James W 7 M KY
Gross, Victoria E 6 F KY
Gross, Richard V 4/12 M KY
Lee, John G 17 M KY
Pleasant Gross (age abt. 22) is not listed in the 1840 Clinton County, KY census, but there is a Simon Gross listed that has a male age 20-30 in his household. I'm pretty sure that this Simon is from the Surry/Yadkin County, NC Groces/Grosses which trace back to a Simon Gross b. abt. 1711 who came to America with his brother, Theobald Groce, in 1741 on the ship Europa. You can see a brief listed of a few "unconfirmed" descendants of this Gross family that I posted on the GenForum board awhile ago:http://genforum.genealogy.com/gross/messages/1129.html
It appears that you may descend from Simon (b. 1711) -> Theobald -> Simon -> Pleasant -> Vienna ...
I'm not researching this line, so I really have no more information on them ~ but I know there are several people out there that descend from this particular Groce family, so you may want to look for postings on Simon Gross/Groce. That should give you some leads to look at. Good luck.