My first bolt-up was as instructed, (without any gaskets), and some copper high heat spray on Permatex...
However... because the straight plugs on the Vortec heads are very tight to the spark plug 45 degree wire caps, the
Remflex 2004 Exhaust Header Gasket provided an extra 1/8", after compression, for plug boot clearance.
The Remflex are fragile and will break easily, so handle them once during install and try to leave them alone after re-torque...
EAN: 0878891000610
The ARP 100-1110 bolts worked perfect with a touch of copper anti-seize, (The bottle with the brush on version, not the spray gasket, mentioned above)...
So... BEFORE you mount the headers, and ruin the gaskets by taking them off and on so many times...
Use a ball peen hammer and torch, to heat and form 3/4"-1" round dents into the #2, 3, 4, 5 @ 1-5/8" areas where the plug boot WILL burn up... unless you bought angle plug heads...
The dents have to be very close to the primary flange to work.
If you are running TBI or FI, you're going to want to weld at least one O2 sensor bung, pointing straight up on the driver's manifold BEFORE you complete the installation, (so you can wire up the three wire O2 mod and a relay, for better idle and faster start up... later). The O2 heater should point straight down, wires up, or it will get clogged with carbon...
Had no idea when the Sanderson's showed up, they were really designed for angle plugs... with a lil' massaging, they fit and work OK using stock ACDElco 8mm wires. Been a year with no issues... Those expensive ceramic wires were in my shopping cart for a while now, however they were not required, so far.
Went with MR43LTS Marine plugs, for now. Have not tried the short Accell's yet, so not sure how they perform... They may be an option, however they are very $$$. The marine plugs run toast brown and can be had off AZ as a set for cheap...
Good luck with the Rosebud and hammer... Just take your time and don't go wild with the torch...
...For what it's worth, they worked well with 2-1/2" primaries, giving me excellent room around the small version GM starter.
They allowed me to eliminate the Y-Pipe and run angled pipes down, curve around the frame, and tuck the mufflers under the side boards.