Edelbrock RPM vs. E street vs. Stealth?

Not going to be too much of a help. I do know the rpms. have a ductile valve seat vs. the e street which has a cast seat set up. In my opinion from what I know the ductile will be a bit more durable. No matter which ones you decide plan on spending some money to have a quality valve job done. There are several posts through out the web site discussing issues with the bolt on and go heads. I personally went with the rpms for my build.