Good compared to Sanderson or Headman shorties, but there are tight spots, especially in an A-body. Most important for the OP, they do not just drop in the place of the exhaust manifolds and bolt up. They go in from underneath and will need a special headpipe which can be purchased from TTI or made by a shop.
I may be wrong, but I heard from a person that used them that they drop in from the top, just like a manifold. No tricks, no gimmicks. TTI also sells the head pipes that extend to the cross member like a full length header.
