RE: Tuning tips, glow plugs and break-in on the LRP spec 3
For 20% fuel, use a medium plug. For 25 or 30% use a cold plug. I've been using OS plugs, they seem to last longer than other plugs I've used. Break in should be like any other big block - once you have the needles set so its very rich but will still run: easy. At least compared to small blocks. Not that I have the spec 3, but I am sure its not much different than the 2.
In case you haven't read this yet: [link=http://www.rbmods.net/enginetempering.php]RB Mods engine tempering[/link]