Edelbrocks are fine, or the RHS heads from Brian at IMM. But what people are saying is you should have them checked by your machine shop before bolting them on the engine. Being a mass produced item things often slip through the cracks.

I didn't have mine checked, and mine were fine but I was taking a gamble and I knew that. As a broke college student it was my only option.

If you get the RHS heads from IMM, Brian assembles them, so they would not need to be checked again.