Hi wilwil, welcome to Rootschat.

As the marriage was in 1749 (two transcriptions I have seen give his wife as Rebecca SHOW), there must be a chance he was the Henry CAM bap at Grantham 28 Dec 1727 (son of John and Mary).
Candidates for Henry's parents would seem to include-
John CAM and Mary FLAW, 1 May 1716 Grantham
John CAM and Mary READE 29 July 1718 Grantham
It seems a common name in Grantham as there were also John CAMM marriages there in 1731, 1735 and 1737!