Popping above 4500rpm

[SHADOW]

I've got a popping problem with my GN and i've run out of ideas.
Anytime i go over 4500 rpm in any gear i get a miss or a pop. Directscan and Scanmaster show anywhere from 1-4 degrees of knock the entire run. O2s are 830-820. I'm only running 14 lbs of boost with straight 110 and joe Lubrant street chip. It does the same with the ME-R on it too. I've replaced wires, plugs, coilpacks, modules, fuel filter, rebuilt the fuel regulator and put in a new 340 pump. I pulled the intake off to check the cam and lifters and both look good. I also installed some adjustable pushrods and set the preload to .035".
I put a set of Champion iron heads and intake on along with a set of Cometics.(new 980 springs too) I'm starting to wonder if there's a problem with a head gasket. It does'nt leak water.
My TE44 is getting pretty sloppy also. I noticed some oil in the intake when i checked the cam. Would oil in the comb. chamber cause this bad of a pop?
Here's some of the combo: TE44,55s, 340 pump, 206/206 Webber, Champion irons.
TIA!

 

[Grandnat]

I am having a similar problem and I noticed that 4500 rpm was when mine starts to act up too.

I also noticed alot of oil in the intake and this will be one of the problems I will be addressing to solve this problem

one thing you might want to check is the seat pressure of your springs. My springs are new and checked out fine, however I noticed my installed hieght was too much, and this made the seat pressure WAY too low.... which caused valve float.


just a suggestion.

 

[oldhotrod]

oil in intake

when i had my eng built,my plenum worked,egr removed.i was told not to use pvc because it would suck oil from intake put it in the plenum and this would lower the octane,you said you had oil in your intake,just wonder if this could hurt you,or any one who gets oil in plenum from pvc

 

[SHADOW]

I just finished checking the springs and they are at 1.700".
Next is a leakdown test. I'll do a search on the pcv valve. Never really thought about it.

 

[2QWIK4U]

This may or may not help but here goes.I had the same prob years ago and after much head banging and replacing every part I could think of I finally found that my exhaust manifolds were warped.Under normal driving and cruising I couldn't tell I had any kinda leak.As soon as it got around 4000-4800 rpm it would pop.I put gaskets on them and it didn't help,took them to a machine shop and laid a straight edge across them and man they were way off from being straight,don't know why.Drivers side was the worst but both needed surfacing.Cost me about $50 but they machined them flat and it stopped the popping that had been such a mystery.I didn't see in your sig. if you have stock manifolds or headers with the GN 1's.Just my O2,hope it helps.