Trying to check into the factory installed valvesprings on 2007+ new body style trucks on 5.3's with #243 casting heads

Anyone have any info on whether they come with ls6 or ls2 valvesprings or do they have a stock type spring.

 

no they do not have the yellow valve springs. They're just normal truck springs that are only rated to .510 lift of something lazy like that.

 

I dont want to *assume* they are normal springs because they dont have the yellow stripe springs. GM has a tendency to change a part on different applications but I want to see what the coilbind/installed height/open and closed spring pressure is on this stock spring.

 

then get after it and do some testing...

 

when i was changing out my springs i placed both of them side by side and the 918s were around 1/4 to 1/3 inch taller then the stock ones....the stock springs have a blue stripe on 'em...

hope this helps

 

I was wondering that too since they are #799 casting heads which are the same as the #243 castings. I would imagine they are standard springs and not the LS6 valvesprings. But its GM and who knows! If I ever have a valvecover off I will check the IH and seat and open pressures. I ran an LS6 cam and springs on my SS for 6 months and I still have their IH and pressures wrote down.