sorry I know this has been asked a whole **** loads of times. Buy anyone know the stock spring rate of a 1LE and IROC/Z28? I did a search but came up with nothing. Thanks.

 

Here ya go buddy:

The stock 3rd gen front coil spring rates are around 350lbs/in for base cars, and around 548 lbs/in for IROC-Z /WS6 cars, 4th gen WS6 cars are around 360lbs/in.The stock rear coil spring rates are around 204lbs for IROC-Z /WS6 cars
On springs, the last 2 characters are the rate.
(Rumor has it that IROC "BZX" front springs are 3" shorter than stock '82 springs)

Front Springs
“XX" is the lightest, and "ZZ" is the heaviest)
6ZW&7ZW springs are the highest sping rate
The stiffest 4 springs ( ZW, ZX ,ZY ,and ZZ ) are all replaced by a single part # GM(14029399)

Possible front springs for a 87 RS w/F41 Suspension or a 87 Z8 w/ FE2 Suspension
Part No. Tag Part No.
-------------------------------------------
14029399 BZY 14029399 -------------- (+) Highest load rate
14029398 BZX 14029398
14029397 BZW 14029398*
14029396 CDB 14029396
14029395 BXY 14029396*
14029396 BXX 14029396*-------------- (-) Lowest load rate
-------------------------------------------


Rear Springs
("UZ" is the lightest, and "NB" is the heaviest)
The stiffest two springs NNM & NNB are only used on the FE2 & F41 suspensions.

67 RS w/F41 susp
87 Z28 w/FE2 susp
Prod# Code Service #

Possible rear springs for a 87 RS w/F41 Suspension or a 87 Z8 w/ FE2 Suspension
Part No. Tag Part No.
-------------------------------------------
10018083 NNB 10018092*-------------- (+) Highest load rate
10018092 NNM 10018092
10018091 NNL 10018091
10018093 NNN 10018091
10032969 NYB 10018091 -------------- (-) Lowest load rate
-------------------------------------------

From what I've read, the 1LE's I left over there are the same as the Z28 springs. I say you keep your 800's in the front, go stiffer in the rear. Ground Control sells specific rate front and rear springs for $55-$59 each, fronts 650lb to 1200lb (higher on custom order), and rear 125lb to 300lb. You should get em in by our next event if you order soon. Just be aware that going too stiff might cause too much oversteer (like thats bad for us lol). I'm gonna go with 250 lb in the rear. Since you're crazier than me, I say go 300lb in the rear.