I have a 2004 mustang v6. Its the 3.9l and im looking to lower it. Whats the proper and safe way to do this.

 

Define proper?
I suppose heating the stock springs is not the most proper.
I have on many occasions just cut both stock and aftermarket springs to meet what I wanted.

But in the purest answer to your question,.. Purchase aftermarket springs that give the desired ride height that your looking for.
H&R Sport and Eibach Sport line drop these cars about 1 3/4 to 1 7/8 inch after they settle. The stock suspension doesnt allow for too much more before it bottoms out. In many cases the rubber isolators and snubs are removed in order to reach the maximum drop and still have at least some suspension travel.

Hurst

 

Get a good set of CC plates too, reaching desired positive Caster with stock stuff is difficult and it's crap hardware anyway!

 

And a bumpsteer kit!!

 

i thought i might need cc plates. What are bumpsteer kits

 

All very good answers.

Many lowered cars with rack and pinion steering experience bumpsteer. The tie rod ends were designed to be level or just above angle with the front lower A-arms to remain centered with the wheel hub. In many cases on severe drops the tie rod ends are now at a negative or upward angle below the hub. With this upward angle anytime the suspension travels upward from a bump the wheels go Toe in (cross eyed). No alignment in the world can fix this,.. not even with caster camber plates. Fox body cars tend to suffer from bumpsteer more than SN95 cars do. Bump steer kits relocate the tie rod ends and put them back into the correct geometry they need to be in for the steering to work correctly.

Not all lowered cars need bump steer kits. Much will depend on the extent of the drop and how the car handles after the drop. We had H&R Sport springs on my wifes 96 Cobra with 1/4 coil remove on all 4 springs. The car was low. But never had any bump steer issues and never used a bump steer kit or CC plates. Each car is different. Take it one step at a time. Only purchase what you need to have, unless you have money to blow then knock yourself out.

Hurst

 

im looking at 1inch to 1 1/2 inch. maybe 2 inch drop

 

airbags?

 

nope just some new shit. I wish i could have it as low at a vette.

 

many people don't put cc plates on after adding lowering springs cause some clown at a major auto repair chain will say "We got it set CLOSE to factory specs!" Drive a new edge with 2 degrees of + caster then one with 5 degrees and get back to me and say which was better? There isn't enough adjustment with the stock stuff and Ford gives such a big range when it comes to "Within spec" Also getting
-1 degree of Camber is close to impossible without plates!