If I were to purchase the sport version shocks for my 2003 G35 sedan non-sport version, would I also need to replace the coil springs or are they both the same?

Tom

 

Depends, If you buy knee high socks, you won't need to replace your springs because the socks will cover them.

 

I would go ahead and buy the springs too. The 05+ sport springs have a higher spring rate. You'd benefit from the combo. IMO yes, just go ahead and do it.

 

Coupe sport suspension changed in 05. The sedan did not.

With a 31lbs and 34lbs front and rear rate differance between sedan sport and non sport, no reason you can't run sport shocks with non sport springs. Where I disagree comes to a few aftermarket spring kits for the sedan that remove ride height AND have softer spring rates then oem, that I'm not ok with.

 

I think the sway bars are slightly thicker on the sports as well, but definitely by the springs too, they are a different rate.

 

03-04 sedan's all have the same sway bars reguardless of sport or non sport suspensions. In 2005 all sedan's received different sway's, again reguardless if they have the sport suspension or not. So for a sedan, the sport suspension is a shock and spring package only.