Here is my LTC config file. I'm not 100% sure, but I think the important values are "pools", "kernel", "scrypt" and "scan-time". The rest can be left out.
{
"pools" : [
...
],
"intensity" : "13",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "0",
"thread-concurrency" : "0",
"shaders" : "960",
"gpu-engine" : "0-0",
"gpu-fan" : "0-85",
"gpu-memclock" : "0",
"gpu-memdiff" : "0",
"gpu-powertune" : "0",
"gpu-vddc" : "0.000",
"temp-cutoff" : "95",
"temp-overheat" : "85",
"temp-target" : "75",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"log" : "5",
"queue" : "1",
"scan-time" : "6",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"load-balance" : true,
"kernel-path" : "/usr/local/bin"
}