how to tell stock valve springs from aftermarket
 

is there any way to identify stock valve springs from an aftermarket set?

Best thing to do is take a spring to an engine builder and have it checked out, he will measure the P.S.I. both seat pressure and open, takes a few seconds.

well it'll be at a engine builder, that's the issue...so what are the stock spring measurements for those?

stock springs are blue or yellow so it should be easy to tell what is stock vs aftermarket

ls3 spring specs:

From the GMPP catalog

12586484
Valve Springs (not shown)
• Beehive style springs • Standard LS6/LS3 springs
• Use cap P/N 10166344 • 1.250" @ 295 lbs. pressure
• 1.800" installed height • Max lift .570"
@ 90 lbs. pressure

So just looking at them the stock springs are blue or yellow? The whole spring? You're sure?

well they are when new, but you should see some sort of coating/paint on the springs. i'm positive they are blue or yellow as i have removed yellow springs from my engine and replaced them with blue springs

there is no difference between the yellow or blue springs aside from the color of the coating/paint

google it if you are still unsure

+1 This and whatever color the valve spring is.

These are the stock bee-hive springs (not dual springs):

http://accelerationtech.com/photos/p...ps9aa712f5.jpg

New they may have been blue or yellow but, not with miles ;o)

Aftermarket depends on brand. These are BTR dual spring .660 with titanium retainers:

http://accelerationtech.com/photos/p...ps54388f3c.jpg

http://image.chevyhiperformance.com/...ve_springs.jpg

GMPP (Chevy):

https://i5.walmartimages.com/asr/9c8...d&odnBg=ffffff

Bee-hive next to a dual spring:

http://image.chevyhiperformance.com/...ve_springs.jpg

Some aftermarket springs can be a bee-hive design, thus it depends...

Hope that helps...

-Don