Performance loss from headers to HP manifolds

Pulling the headers and then putting them back on is not an option, once they come out, they are staying out, the Mopar Performance headers fit like crap and were a real bear to get in the driver side. I guess I will put the manifolds on since I have them, and try it out. If it doesn't work out then it will be a toss up between TTI and Dougs headers. Thanks for all of your opinions.