My preference is Hedman Hedders 69260 ( web page ), but as several folks pointed out, Hookers work street corners and just about any headers made for that application will do just fine, including rams' horns.
P/N 69260 for your application
I've used Dynomak, Hooker, Edelbrock, "no-name" and Hedman. I've never had a bad experience with Hedman.

No, I don't work for them. Hey...I don't even work...I'm retired. How bout dat? It feels good to be able to say that, since I've been fighting for disability retirement for 15 months and I'm sposta start gettin an income at the end of November...finally!