Here is some good Kentucky Windage and Tennessee elevation type information Kevin. The images below are from SCE gaskets. Other than one website image, which I have spoken to them about, and they agreed was incorrect but still have not corrected it, the other stuff they show is accurate. I'll flag the upside-down image when we get to it.
This is a general guide to what to use for various engine boost levels. Boost is a broad but, also good indicator of how heavily you are working the head gaskets.
As you can see, SCE recommends MLS or their ICS Titan Gaskets up to about 25 lbs of boost. Above that boost level they recommend either their Titan or Pro Copper gaskets. Your boost is solidly up in the Titan and Pro Copper space.
The ICS Titan gasket uses an o-ring made of stainless wire that it is embedded in a cut channel on the ID of the gasket's bore. The gasket sandwiches the o-ring, so it is squeezed into the upper and lower layers of the copper gasket surrounding it. This is a nice gasket design and although they show it as identical to an MLS for sealing capability, I have found it to be slightly better than an MLS but not as good as their Titan or Pro Copper alternatives. This is what the business side of the ICS Titan gasket looks like;
The SCE Pro-Copper and Titan-type Gaskets are the gaskets we historically have associated with supercharged alcohol and fuel engines. They are simply dead soft copper sheets cut out with bolt holes, and cylinder bore holes for use in highly boosted applications. They require the use of a stainless wire that is fitted to the head for compressing the copper into a corresponding receiver groove in the block, more on that in a minute. The Titan gaskets have additional seals for oil and water passages in the heads and block. The Pro Copper gaskets do not, they are for pure race applications.
The Pro Copper and Titan gaskets are the gaskets that SCE shows the o-ring being located in the block rather than the head. When I spoke to SCE at the last two PRI shows, they told me the o-ring should be located in the head and the receiver groove located in the block — which is the way I have always used this type of gasket. When I Informed them that their website showed just the opposite, they were initially unbelieving. When I took out my notebook and showed them the page they said it should be the other way around i.e., receiver groove in the block, wire in the head. They said they would look into correcting the imaging. As of today, it remains uncorrected.
This is the prep and dimensional information for this type of receiver groove for the stainless wire;
This picture is the pic that is incorrect. It illustrates the stainless wire being located in the block deck when it should be in the cylinder head — especially on Aluminum heads. If you put the o-ring in the block and the receiver groove in an Aluminum Head the harder copper gasket material will mush out the receiver groove in the Aluminum Heads and ruin a set of otherwise perfectly good heads. The damage is irreparable, and the heads must be replaced.
The sizing metrics for the wire are correct. For the Boost levels you are running the 0.041" wire will be unsuitable. You will need the 0.062" wire to seal up your chambers.
This pic shows an 'assembly' view of the gasket, stainless wire, and
what should be the head but is illustrated and labeled as the block
The correct assembly sould locate the stainless wire in the head and the corresponding receive groove in the block. If you do it the other way around you will destroy a set of otherwise perfectly good heads
Other than the misdirection for the proper location for the stainless o-ring wire in the picture, everything else is correct.
When you modify an engine for this type of gasket usage/sealing tech, you need to have the o-ring receiver grooves in the block and the o-ring anchoring grooves in the head properly positioned for registration and sealing. To do this, the shop needs to use a Bridgeport or other similar precision machining center to accurately locate the receiver, and o-ring grooves in both the head and block or they will not seal, and you will torch a head and block.
This is a dimensioned drawing of where the grooves must be located for a 100 mm bore center block like a Modmotor. The dimensions are for an 0.041" wire o-ring. If you intend to do this, I can provide you the correct dimensions for an 0.062" wire o-ring.
If you give this drawing to the machine shop, take the extra effort to insure they know how to cut your o-ring grooves. Once they are cut wrong, you can not 'uncut' them, and you will need a new set of heads. Properly installed in your heads, the o-rings will look like this, except they will be Modmotor heads and not T/F heads.
This is a pic (below) of a set of new SCE Titan copper gaskets showing their proprietary coolant seals and how the stainless o-rings force the gaskets into the receiver grooves as you torque the heads down. At this point, the depressions are the result of only lightly tightening down the head. The engine below is AJ's, (Mofasta), and you can clearly see how the o-ring begins to push the copper into the receiver grooves at the top of the block, creating an interlocking seal.
When everything is said and done, this is a lot of expense and effort to seal up an engine. It is also improbable you can hook up all the power this engine is capable of producing, on the street. Of course, the easiest and least expensive way to address this problem is to turn down the boost — although I also recognize how hard a decision that might be