I know this has been asked a lot but here is the situation.

Arrive to LHR from JFK at 6:25am.
Depart for LGW for DBV at 9:50am.

It's Friday, July 24th. Is it possible to make the connection? I know the National Express, etc? Or is it too risky?

Damn BA does not fly anywhere tropical out of LHR but only LGW.

Thanks!