[PontiacHO]

Ordered finned aluminum valve covers for my 68 Firebird 350. The breather holes are in the ends of the covers, not the centers. Would y’all stagger the breather holes or does it matter? I know the drivers side breather will have to be in the front due to clearance with the brake booster. FWIW-tired of flimsy tin valve covers that will leak.

[72projectbird]

It's just personal preference. I'll usually stagger them as I like the look.

[PAUL K]

I usually put them towards the front. Less oil contamination up front. I personally feel it looks better, like you have a pair of of valve covers rather than a universal set... Front location won't work with A/C

[steve25]

My thoughts and concerns are these.
In terms of oil leakage if your do not want your breathers to at some point being overwhelmed by oil shorting right up out of the rockers you need to have the stock rocker arm baffles on the heads.
Why?
The stock valve cover holes are located centered because there are no rockers right in that location to blast oil due to rev’s above 3K right up into the open bottom of the breather .

if you don’t have that baffle or make and epoxy a baffle in your new valve covers you will be at some point dealing with a oil overloaded Leaky breather.

The holes for breathers on the ends have a rocker right under them.

This is what these factory baffles look like .

Hopefully you have them, but they do need the stock head bolts being used since that’s what they bolt down to.

If you don’t not have them then as I posted above make a thin sheet steel baffle that has folded over 1/4” legs to stand them off the valve cover enough to clear the bottom of the breather.

Another bad thing in terms of oil control is if you are still using the stock air cleaner you loose that vent tube .
The vent tube is used so at full throttle the vacuum of full throttle being applied thru that tube helps to keep a negative pressure in the motor .

[PontiacHO]

Supposedly these come with baffles. The hope is the baffles will clear my poly locks. I have an aftermarket open air breather so no PCV vent tube.

[steve25]

Well if need be go the thick gasket route with valve cover studs and not the normal bolts .

In regards to your poly locks are you using them on the stock bottle neck studs?

[PontiacHO]

Yes, Cheap Pioneer poly lock nuts with stock valve springs and 066 cam. Not a lot of stress on the studs. It’s a cruise car.

[steve25]

Good that you have only .406” lift!

I found out the hard way that .470” lift with poly locks and stock bottle neck studs will get you stuck on the side of the road .

[PontiacHO]

New valve covers won’t clear rocker arms with baffles that came with them. Going to try these.
https://www.autozone.com/emission-co...0aAvF1EALw_wcB
I may be wishing I’d just resealed the original 57 year old covers.

[3X24SPD]

Those baffled grommets are just going suck more oil through the PCV.
They are so tall that they pretty much bottom out on the head where all the oil is.
What you need to do is raise the valve up out of the valve cover.
I CAD modeled a simple extension & 3D Printed a bunch of them.
The extension uses a std breather grommet in the valve cover and
a std PCV grommet for the valve.

[GordonGeesey]

I too ordered those finned valve covers for my GTO bc they looked so cool.

Red flag #1) The bolt holes didn't line up, so I had to drill the existing VC holes oversized.

Red flag #2) I run Scorpion-brand aluminum roller rockers. They hit the inside of the valve covers, forcing me to use to die grinder to "clearance" them.

Red flag #3) The supplied screw-in baffles hit the rocker arms as well, so I could not run them. The holes for the breathers are directly over the rocker arms, so the cool breathers I installed leaked oil as soon as I drove the car. What a mess!!

[PontiacHO]

Shoulda coulda woulda. I may send these valve covers back. As much as I like the look, I’m not going to modify them especially just to bolt down. Seems like the finned aluminum covers with center holes are $500. That’s beyond my budget.
How are the aftermarket chrome replica valve covers like what came on a 400? Thin?

[steve25]

Gordon you had the same wonderful experience I posted about back in #4.

That fun led me to tall Moroso chrome ones that I still had to form and epoxy a baffle in, but at least they cleared my Harlen Sharp rockers and where much easier to wax and keep shinny then my blower was!

[64speed]

The Edelbrock finned valve covers clear just FYI

[3X24SPD]

Originally Posted by GordonGeesey

I too ordered those finned valve covers for my GTO bc they looked so cool.

Red flag #1) The bolt holes didn't line up, so I had to drill the existing VC holes oversized.

Red flag #2) I run Scorpion-brand aluminum roller rockers. They hit the inside of the valve covers, forcing me to use to die grinder to "clearance" them.

Red flag #3) The supplied screw-in baffles hit the rocker arms as well, so I could not run them. The holes for the breathers are directly over the rocker arms, so the cool breathers I installed leaked oil as soon as I drove the car. What a mess!!

Are you guys talking about this style Valve Cover?

[b-man]

Originally Posted by PontiacHO

Shoulda coulda woulda. I may send these valve covers back. As much as I like the look, I’m not going to modify them especially just to bolt down. Seems like the finned aluminum covers with center holes are $500. That’s beyond my budget.
How are the aftermarket chrome replica valve covers like what came on a 400? Thin?

The aftermarket reproduction chrome 1967 and later covers aren’t thin and flimsy, they’re comparable to stock originals. At least with new covers you’re starting with nice flat gasket surfaces without sunken bolt hole areas hat need to be straightened.

Myself I have some decent original chrome 1964 GTO covers on my 421 with double 1/8” rubber gaskets using Gasgacinch between them. I glued them to the covers with Permatex Hi Tack and smeared a thin layer of grease on the side the seals to the head. The reason for the double gaskets was to clear the polylocks on my Crower 1.5 rockers.

No leaks so far, perhaps the additional compressabilty of the stacked rubber gaskets helps seal the covers without distorting them with excessive tightening who knows.

Now you know why GM went to all cast aluminum valve covers, oil pans and valley covers and captured o-ring type gaskets on their LS series engines. They don’t leak.

I took these pictures while I was replacing the driver’s side valve cover, I wanted to install the California Emissions PCV breather tube so I needed to swap to a cover with a breather hole. My builder had used Gasgacinch to adhere the double gaskets to the blanked-off cover so they easily peeled off for reuse. With only about a thousand miles on them there wasn’t any reason to toss them, I kept them in the same orientation and so far so good.