We have done the BB Chevy kits and used Hemi flanges as well as the Hedman kits.Hedman gives you quite a selection of bends and their 3/8 flanges with a 3+ inch stub pipes give you an excellent starting point.You can buy complete slip on collecters and weld or bolt them on and make that part of header making easy.You won't find the mopar kits in Summits cataloge but have to talk to a saleperson.The flange kit is aprox.$175 and the tubing kit is aprox $275.It beats the heck out of a $1200 set of custom headers and most all shelf stock Hemi headers run $800 and up.TTI makes the best fitting shelf headers.