I finally convinced my dad to let me do somethings to his sc400 i was just wondering what order of mods the 400 guys usually take. im already in the process of building him a custom exhaust with no cats and probably some nice magna flows and 2.5 for piping. also his intake is already on order. keep in mind he doesnt want to go forced induction but want a decent amount of power. do you guys think an safc would be a good next step? maybe plugs and wires? i expect david to chime in here some time

i appreciate the help guys

 

in my opinion.... Magnaflows sound horrible! raspy and annoying.... check out Borla.

 

To make sure that all the maintenance is taken care of is first on the order, even if it's expensive and relatively boring.
Intake, exhaust, well tuned piggyback computer will all work together to make a car that's too fast for the stock suspension, but you can do a search for that one.
You don't have to spend crazy $$$ either, even though most do on expensive aftermarket parts that do little for actual performance, and are more for pimpin'.