Grooved is always best. But it depwndes on how much boost and how much HP. I've put over 500hp to the stock replacements from autozone with no problems.GET IN THE ZONE !!
Depends on how much boost is anticipated.
Personally, I do not like to cut grooves in the heads.
The gaskets are $$ and I've heard that they can develop seapage(spell) fairly easily if the grooves are not cut with a magin of error.
I've never had too many issues, except with the 347s. They seem more prone to blow headgaskets out.
I heard that o-ring gasket will cause you to melt a piston if you dont have you tune right, otherwise if you used non o-ring head gasket you would blow the gasket. has anyone else heard this? What would you recomend for 12lbs of boost?