New heads

Tho I run stock heads on my 318,lots of guys are going with Speedmaster because of price.
Too many horror stories about out of the box heads having flaws is why many pull them apart and check them out completely. Even good names such as Edelbrock and Trickflow .
I bought a set of Mopar Performance big block heads and out of the box each head had different pressure valve springs.
That was 20 years ago. Quality Control was as bad back then as it is now.