well, i have an 05 sport, the spring rates are very close(higher in the front though). from the suspension sticky: I will take some pics Wednesay after my allignment (hopefully they will have settled already)

 

did you preload the suspension (or do you even have to?)
I know when I installed springs on my rx8, you had to preload the springs to get it to settle correctly, I used a jack and raised the rotating asembly up while the A bar was loose after the spring was fully compressed and the car started to life up you tighten that A bar, and thats it. or you leave the 2 bolts for the bar loose drive it around the block, turn the wheel and tighten them.
I didnt have to do this for any of my other cars though.

and I have a 04 sport, but I kinda want a stiffer spring. I am think about the z swift springs now that I hear the z stechs arnt much of a improvement.

 

Oem linear springs
G35 coupes with oem 17’s & 18’s
G35 sedan’s with sport suspension
350Z’s 2003/2004
Front:314 Rear:342

Swift 350Z linear springs .8”/.6” drop on 350Z, G35 drop will be higher)
Spring rates in LBS 336/364

Tein S-tech 350z (fronts are progressive, rears are linear) .7”/.6” drop on 350Z G35 drops will be higher
Spring rates in LBS 386/402 (estimated front intial rate is 327lbs)

S-techs would be stiffer for your car

 

Looks good bro. Spacers put the wheels out there just enough. Nice drop too.

 

oh I see, thanks man,
where are you getting this info?

 

no worries, 3rd sticky of the suspension/brakes subforum... lots of info on there