I tried to install a set of Hooker headers on a big block B body Mopar about 30 years ago. They didn't even come close to fitting. I think one tube ran right into the steering box. I worked on them for a while and even took them to a shop to change one of the tubes. But it didn't end well so they ended up going into the dumpster. It was a lot of money for me to waste 30 years ago. Left a bad taste in my mouth and I've never used anything from Hooker since.