Put some valve springs on a friends 4.8 were working on. Went by without a hitch. But one concern I had is this. On a few of the cylinders I could hear air hissing a bit. Is this a bad thing to have on a motor I just put feaking heads on??

 

hrmm when was the air hissing, was it only hissing when you were using air to hold the valve up?

 

Only when the air was hooked up.

 

hrmm might just be a small hole in the line you were hearing did it do it on every cylinder??