I've seen many cossies running 300+ bhp with std gaskets

imo its a lot of hype gasket failer is mainly due to the early 2wd heads not being that good around the water jacket area...and people drivin cars when they know they have a problem eg leaks overheating etc

And poor fitment surfaces must be spotless and a good quality torque wrench should be used

I personally cannot see any difference between a std and a grp a only the numbers