Is this correct?

I run forged pistons and they can (but mine don't) rattle around in the bore or sound like a diesel. Forged have a diferent thermal expansion rate... A bit looser when cold but correct when warm.

But....

Forged pistons are not needed for most street/moderate track builds and they will not make your car faster.

Forged piston can take a higher level of detonation before failing. This is not such a huge bonus as you engine should be tuned not to detonate in the first place.

As far as a 273 having forged pistons.... I don't know...... Most factory engines (except some high compression or force inducted engines) had/have cast pistons.

So unless you are running on the edge of the compression for pump gas they would be a waste of money.