Indy/RHS had LA-X heads years ago which accepted LA intakes and valvetrains with closed chambers and Magnum valve sizes. MA-X was their Magnum version. Hughes may still have some.
[URL]https://www.hotrod.com/how-to/mopp-1003-360-x-cylinder-head/[/URL]
[URL]https://hughesengines.com/TechArticles/8laxandmaxironsmallblockheads.php[/URL]
Is Indy planning on another cast iron LA head?