They were definitely worth it for me as at the time I had cracked manifolds on a 60K mile L31 and Thorley was not making the Tri-Ys for the Express chassis yet. A quality set of headers withstand the heat better than the thinly cast GM garbage as well as flow noticeably better. On a 1500 though, it really does not matter power wise what is there with the restrictive stock head pipes and cats in place. On my brothers 99 Suburban we re-used the JBAs I had on the van, hooked them up to the Hooker 2-1/4" dual exhaust system they made for the GMT400s and replaced the GM cats with a set of Nissan Titan rear bullet style cats that I had that were practically new. Really woke that suburban up. The Titan rear cats flowed well enough to make ~300 rwhp on the Titan, even with the manifold cats in front of them. They were a big improvement over what GM used.