Well, I knew Les would chime in, since he has been there done that. Just so you know, about 45 min from me is a shop who have been building headers since the early 60's, from monster truck to some of the best drag racers in the world. Our problem is not just the fact we are not going to get a big return, but the room to even think long tubes. Their quote to me, and I love their work, was 2500 bucks. I would have done it for half that, but for that, I am doing a gear change in the rear end. As for shields, not even room to place your fingers in there let alone a wrench. So clearances are a huge issue, that is why I stated the heat issue as you are very close to everything trying to get down to where the collector will be. Once you are at the collector, then it is muffler shop time....no biggy there...

I will add this...in all my old days of muscle cars, headers were usually in the mix of mods we all did. They were always a pain from the burns we all had working around them, but they did add some HP....but 70 is ridiculous... Everyone car manufacturer in world would put headers on their performance cars if this were true. Think about that for a second. 20-30 is and always was max in our day...and I can't see that changing today with computers no less....