Perhaps this will help clarify the question of "new" vs. "old" early 2004 model 350z suspension parts. According to the dealer, there IS a stamping number on the shock body. The stamping number is similar to, but NOT the same as, the actual part number.

Here are the current and prior 350z part and stamping #'s:

FRONT SHOCKS

FRONT SHOCKS
08/2003 - present
All models

Front Right - P# 56110-CD725, S# 56110-CD700
Front Left - P# 56110-CD726, S# 56110-CD701

superceeds

FRONT SHOCKS
06/2002 - 08/2003
All models

Front Right - P# 56110-CD027, S# 56110-CD004
Front Left - P# 56110-CD028, S# 56110-CD005
__________________________________________________

REAR SHOCKS

REAR SHOCKS
08/2003 - present
All models

P# 56210-CD325, S# 56210-CD300

superceeds

REAR SHOCKS
06/2002 - 08/2003
All models

P# 56210-CD026, S# 56210-CD021
_________________________________________________

FRONT SPRINGS

Note: Regarding front springs - there are no stamping numbers to reference, however these part # changes should be noted:

FRONT SPRINGS
12/2002 - present
Coupe models (ex Roadster)

P# 54010-CD003

superceeds

FRONT SPRINGS
08/2002 - 12/2002
Coupe models (ex Roadster)

P# 54010-CD002

superceeds

FRONT SPRINGS
04/2002 - 08/2002
Coupe models (ex Roadster)

P# 54010-CD001

FRONT SPRINGS
05/2003 - present
CV (Roadster)

P# 54010-CE400
_________________________________________

REAR SPRINGS

Note: Regarding rear springs - there are no stamping numbers to reference, however these part # changes should be noted:

REAR SPRINGS
08/2003 - present
Coupe models (ex Roadster)

P# 55020-AM820

superceeds

REAR SPRINGS
06/2002 - 08/2003
Coupe models (ex Roadster)

P# 55020-CD010

REAR SPRINGS
08/2003 - present
CV model (Roadster)

P# 55020-AM821

superceeds

REAR SPRINGS
05/2003 - 08/2003
CV model (Roadster)

P# 55020-AM810

REAR SPRINGS
07/2003 - present
Coupe AT model*

P# 55020-CD010

*Notation: "Not Adopted Yet. 18 Inch Tires & Wheels"
_____________________________________________

SUMMARY

So all this would suggest that:

FRONT SHOCKS

- All 2004 Coupe and CV (Roadster) front shocks are exactly the same, and not valved differently. With regard to the possibility some '04 Coupes (and possibly even CV's) used old parts inventory after the 08/2003 part change date (which part changes certainly could have incorporated valving improvements), the stamping number on the front shock should alert you as to whether they are new or old shocks.

FRONT SPRINGS

- The '04 Coupe uses the same spring as late '03 Coupe production, however, since there were three front spring changes for Coupes between 06/2002 - present, depending on how inventory was worked into production it might be possible that earlier '03 Coupes have one of three different front springs!

- It appears that the 2004 CV model used an exclusive front spring from the very beginning of production.

REAR SHOCKS

- all 2004 models use the same rear shock. However, since there was a part # change for all models on 08/2003, due to possible working of old parts inventory into production, it is possible for ANY early 2004 production model (not just Coupe) to have the older shocks. Again, checking the stamping number on the rear shock should alert you as to whether they are the new or old shocks.

REAR SPRINGS

- The rear springs for the 2004 Coupe and CV is different. Additionally, in the case of Coupes, rear spring part number changed on 08/2003 so it is possible that early '04 Coupe production used up old rear spring inventory. Further, in the case of CV's, rear spring part number also changed on 08/2003 so it is possible that early '04 CV production used up old rear spring inventory. The ONLY way to tell which spring you have is to ask the dealer to run the VIN #. The manufacturer must maintain info on which parts were used on each car for recall purposes.

Hope this is helpful.
Peace

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

The part numbers stamped on my 03 Z shock's match with the superceded part numbers you've listed.

I would think you can now request the owners of 04 Z suspensions your thinking about buying, to give you the part numbers off their shocks to make sure your getting a revised suspension, I dunno.

If anyone was willing to send me a single front and rear spring from the revised setup I will find out if and what the revised spring rates "might" be and return them within 48hrs.

"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

Now if other people post their shock stamping numbers and build plate dates, we might get an interesting picture of Nissan production and parts flow. Without running the VIN # though, I think springs are going to continue to be somewhat of a wild card.

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY