Slip fit, so will tick/leak, other than that great quality, great mod for S/C'd cars. PEMS/Powerlogs + down pipe would be a great alt. for a N/A car.
FWIW, it took me about 6hours to do mine, first time installing headers on a FWD. The rear header is where the time comes in. You have to unbolt the dog bones and pull the engine way forward. Do the rears first.
the fronts have SOME clearence issues w/ the a/c lines, but you should be able to "bend" the a/c line w/o damageing to fit properly (only need about 1/4" so it doesnt rub). All in all if you are going headers get SLP or TOGs