340 stock manifold to header adapter question
I had a different issue. Had a set of Appliance headers back in the 70's, that had a reduction cone to 2", but I want a full 2.5 exhaust to the rear. I threw the cone in the trash and had a local shop weld the 4 bolt flange to the head pipe, to the rear. Now I had a full 2.5 exhaust and it was adjustable. In your case, I would have welded the stock flange to the head of your new exhaust system. A local shop will be best to do this for you.
