400 to 451 stroker questions

All of the Mahle (Ma-lah) pistons sold for performance mopar apps are equipped with a 1.5/1.5/3.0mm ring groove.

I have seen .043 rings....but no 1.0mm pistons or ring packs for a 4.375 or 4.380 bore. Can someone show me where they are in the catalog?

Also, as far as I know nobody made a metric "better than plasma moly" ring for a 4.375 bore ten yeaes ago. Only when Mahle came out with the GNS series stainless top ring pack did that get solved.

I have a 1/16 ring pack 451 with standard moly rings that has 50 bottles of nitrous through it. Rings look perfect under a magnifier. None of the moly coating is burned off.

With 1.320CH piston, 4.250 stroke crank and a 9.980 deck 400 block you will be right at zero deck or very close. You will likely need to have 80+ cc chambers to stay in pump gas territory with alloy heads or a .051+ head gasket. My 511 with 440 source heads is 11.5ish CR with a 12.5 cc reverse dome Diamond shelf piston. The other identical short block with ported MW Victors was around 11.2ish CR for reference.

Unfortunately Mahle doesn't have a 1.32 CH piston with a reverse dome. That is how I ended up with a 499 - 4.150 stroke, 1.120 CH flat top and a 6.760 rod. Mahle offers .990 or 1.094 pins. I went .990 becaise I was starting from scratch.

I searched high and low for a modern piston (coated, metric ring pack etc) for my 451 refresh and there just isn't much out there unless you get creative and use a BBC rod around 6.660ish from what I remember.

Keep in mind when looking for pistons that your desired compression height will be (deck height - connecting rod length - (1/2 stroke) i.e. (9.980 - 6.535 - 2.125) = 1.32