what to do ?

My fairly New GPU GTX 770 running at 99% load (BF4) is running at 74c, Is this fine or should I be worried ? .. my CPU cooled by Kühler H2O 620 is running at 56c with 70-80% load. Worth looking into a custom Loop watercooling for my CPU/GPU/RAM ? ...Also how much would it cost roughly speaking. would need to do A lot of upgrades before Watercooling e.g. new case,MoBo,CPU, RAM everything basicly. bought PSU / GPU couple month ago so there fine.

Seems a fairly normal temp.

Of course depends on your airflow and other such factors such as card manufacture etc but depending on the make of card its within a normal range.

Certainly not worth spending the money on watercooling. Temp is fine and won't be throttling anything.

Graphics cards start to get a bit dodgy >100C, can start throttling/shutting down. You're well below that.