IIRC, correct term is A engine or LA engine.

A-engine = poly heads

LA = light weight block casting/wedge head

poly refers to the combustion chamber of the heads.

wedge head refers to combustion chamber.

being called a wide block refers to having larger poly heads/VC and a wider intake which makes it wider VC to VC in the engine bay.

my 73 duster with a poly 318 was a tight fit but did fit in there. the poly steel crank is a good upgrade on LA318 builds.

the magnum also has that odd T-cover hole IIRC.