Here's how to accomplish this for port 80:

access-list policy_nat_http1 extended permit ip host 192.168.2.60 any
access-list policy_nat_http2 extended permit ip host 192.168.2.60 any

static (Inside,outside) 64.141.6.51 access-list policy_nat_http1 
static (Inside,outside) 64.141.6.52 access-list policy_nat_http2

access-list outside_access_in extended permit tcp any host 64.141.6.51 eq www
access-list outside_access_in extended permit tcp any host 64.141.6.52 eq www