Primaries (Headers) for FIA 289

[PCW]

I'm in the process of deciding on a motor and I starting looking at the ERA Primaries and Comp Exhaust. As I started to read different threads about the Primaries, that they would only fit certain heads and height on certain blocks would also pose a problem with the Comp Side Pipes aliment. The threads were pretty old so I wasn't sure if ERA had address the issues over the years or not. Is it best to stay with the 289 block, or would a 302 work as well? Also, I read that Dart heads would not work with the ERA Primaries but AFR heads would work. I would like to use the ERA Primaries and Comp Exhaust but want to make sure I take all this into consideration before having the motor built.

Thanks,
Craig