There excellent intakes as well. Keep in mind, the PErformer replaced the LD4B for a good reason.
I like the LD4B for it's large runners and a no brainer upgrade over a stock iron intake. Though the 340/360 intakes will stand toe to toe with it, you just need a build strong enuff to see a difference.
If it's a low out put build, you'll never know whats on there until you look and feel little difference.
The Stealth is also a excellent part.
Going on a mild 318. I already have the performer as I upgraded to the LD340 on my 67 Dart with a built 360. Trying not to waste my money if you know what I mean. thanks.