I found my great great great grandfather was GIlbert McWhorter born about 1746 in Dalmellington, Ayrshire, and I am now looking for his parents.

Try this website: http://homepages.rootsweb.com/~mcwgen/scotrec2.htm#1721%20to...

Here's an extract from Dalmellington :
" On 7-Nov-1738 a “Gilbert McWhorter” married “Jean Wilson”. On 13-Feb-1743 “Hugh McQuhirtor”, perhaps a son of the same “Gilbert McQuhirtor” was christened. And, on 14-May-1749 “Peter McWherter”, perhaps another son of the same “Gilbert McWherter” was christened. "