o-ringed head..now truck sounds different.

homewrecker

homewrecker

gear jammer
Joined
Oct 23, 2007
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Just got my friends truck back together(99 SO).He blew the head gasket so we went ahead and had it o-ringed/decked and put ARP studs in.I've got 3 retorques on it and gonna do one more after a week of driving it.The machine shop took .008 off the head so we went back together with a standard thickness 24V hg.

The exhaust has a different tone to it now vs before.I'm not sure how to describe it,maybe a touch of drumming,bop,bop,bop noise out the stack.Its just a real mild sound,kinda more like my 01 HO motor.It idles smooth as silk and so far seems to be running great,though it hasn't been pushed hard yet.I haven't got the valve lash set perfect yet being I'm gonna be pulling the rockers one more time for the retorque but they are well within specs.Does any of this sound normal?How much was the compression affected with the .008 being taken off the head? TIA
 
I wouldn't think that little would make any real difference at all?

Just out of curiosity, what did the O-Ring and decking cost you?
 
Lets hope so. I can't really see a couple thousandths on the valve lash causing this though.They are all on the loose side.
 
I'd put money on the valves also.

I'm betting after the last retorque and lash setting it will sound normal again. I read somewhere that you can take up to .009 TWICE off these heads and still be within cummins specs (when mine was decked they also took .008 off, so I was curious to see if it would cause problems)... So I wouldn't worry too much about compression.
 
Valve lash got it.Exhaust sounds nice and smooth agian. This truck runs like a raped ape! Mach 7's and a Garret stage3 are a sweet combo.
 
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