I've installed just about all the headers. Pacesetters seem to have major sealing issues until you weld parts. ZZP headers were a pretty straight forward install although the egr tube location on them is mighty high and I'd be careful when bending that tube that much. Speed Daddy's work well, you need to adjust the firewall and pick up better clamps. If you don't want a ticking flex..replace that while you are at it.
There's a how to thread on installing headers ...at least I think I did one. Mentions lowering the subframe to install. It's the best way I've tried so far.
