Originally Posted by L33T Z34

I'm willing to bet the OEM Nismos are stiffer.

2011 370Z Nismo part numbers ($1,030 total for all parts listed below IF ordered from a discount Nissan dealer. The '09 and '10 Nismo part numbers are slightly different, probably a revision for '11.)
right front shock = E6A10-1A30B
left front shock = E6A11-1A30B
front springs = E4010-1A30E x2
rear shocks = E6B10-1A30E x2
rear springs = E5020-1A30E x2

Nismo S-Tune "Low Down Kit" $840
kit part number = E3110-1EA00US
The part numbers below are what is in the kit. These part numbers can't be ordered separately.
right front shock = E6110-1EA25
left front shock = E6111-1EA25
front springs = E4010-1EA00 x2
rear shocks = E6210-1EA25 x2
rear springs = E5020-1EA00 x2