A G
The CMC and streetbeast are one of the same.
I have a 351 C in my CMC I had to have the headers made by a muffler shop.
I do not know of a off shelf header that you could buy.
I think that JEG'S has a header kit that maybe will work for you.
I got my sade pipes from Bethania Garage in NC.
www.bethania-garage.com 336-922-3018
Tom Beroth.
Finish Line has nice pipes as well.
www.cobraaccessories.com
Both are grate people to work with.
Hope this helps.
Bill