which spark spugs to get?

[bulldog11267mad]

ok so my dad is having a kit cobra built for him. we built the engine. it is a ford 460 roush racing block. trickflow heads and intake manifold. it is 12:1 compression ratio and will be right at 1000hp what heat range and type of plugs should we get for it?

 

[XR8tt]

I would start at 2 numbers colder than std.. Then if there's no plug fouling and look fine it should be right..
Start with Autolite ATL 3922