Cometic Head Gaskets $139.99

[SappySE107]

Correct, i have tables for stock pistons on the product pages

[gectek]

i would not recommend same gasket as bore size, but really tight is good all around.

[pocket-rocket]

I need to clear up what I meant by "the bore match the cylinder". What I meant was have the block bored out to be closer to the bore size of the stock head gaskets. I know that is way past safe, but if it were able to work (don't worry, I have absolutely no plans on ruining a block to try it) it would give a good size boost.

Out of curiosity, why wouldn't you want the fire ring the same bore as your cylinders?

[gectek]

all sorts of problems such as the pistons/bore getting larger and the fire ring staying the same, as well as higher rpm with rod stretch and heat taking over. also the shear effect between the head and the block due to differences in thermal expansion. those are just a few.

[pocket-rocket]

Differences in thermal expansion I can see to a point, but .130 vs .020? I'm not trying to be a smart alec here, just trying to understand why difference in the stock gasket bore vs the cylinder bore is so large a little better. Maybe I should hit up Brad to ask his source at GM powertrain to get a more technical point of view.

[gectek]

maybe im not understanding what you mean entirely.

dumb it up for me please.

[gectek]

wait a minute. before we mess up the for sale thread....start another one
better idea

[pocket-rocket]

Good call.

http://60degreev6.com/forum/f102/head-gasket-bore-size-vs-cylinder-bore-size-t44623#post403381

[ssdurango]

I want to purchase a set of these for my 3.4. What thickness should I order to get the ideal quench -0.025 ok? (Pistons are stock size.)

Thanks
Tom

[SappySE107]

iron head? What is peak RPM?

[ssdurango]

I have the limiter set at 5500, peak HP is at 4600. I guess it could rev to 6500 but wouldn't dare. why do you ask?

[SappySE107]

Iron head?

I ask because you can run a thinner head gasket at lower RPM use.

[ssdurango]

yup iron head...

[SappySE107]

.030" would be good but you can probably run .025" to 5500.

[ssdurango]

Should I get 3400 Gaskets for my 3.4 then? Everything should be the same, right?