Ported 452 or Edelbrock RPM

I would search but recently, I think .029" is what is available, I still don't get why exactly Mopar ditched the .017" coated embossed shim gaskets. They worked perfectly
for a bunch of builds, but they're gone now, so the Mr. Gasket would be it. An MLS gasket would be best, but I think that is the .029" at best. I sprayed a copper coat on
the shim gaskets when I used them, I haven't used them on an Al head yet, but I would coat them for sure to help ease expansion movement. You may be able to run
that @.053" if those pistons are forged, they will expand more than cast slugs & close that up a bit more when things heat up. First You must have an EXACT measure
of the deck height, then proceed. If You can get an acceptable squish, I wouldn't worry if the squeeze creeps up a tad, the increase in burn rate should make it moot.
More importantly, enlighten Me on the rating method for octane there vs here in the States. Our RON+MON/2 ratings We're familiar with, not so much Your neck of the
woods!!

Actually in Europe its RON and in USA and Australia DON is used which is what you described.

I wanted to use the steel shim with permatex copper, if it fails to seal I will go with some MLS gasket which is like 4x the price. I have a fresh set of 1135G, I used these with my iron heads with perfect result. My concern was that perhaps embossed steel gasket will damage the heads.