Motor Build Trouble

My setup is a motor from an 86' with a hydraulic roller cam and adjustable screw in rocker studs, topped off with a demon carb. I just installed a motorsport b303 cam and am having a couple of problems:

1. After 5 minutes of running, the headers glow red hot I thought there was no breakin for the cam?

2. After running for a few minutes, the primary bowl of the carb floods, but not the secondary. I've checked the needle bearing and turned it all the way down, but nothing's worked so far.

3. She backfires like an m-80 when it is shut off, fires through the carb and the exhaust.

Thanks for your help

my engine setup is from a scca autocrosser. its got screw in rocker studs, worked over stock heads and forged pistons.
timing was set with the vacume advance still connected. it was set around 25deg BTDC. dumb mistake, so that should clear up the red hot headers.
i've repeatedly adjusted the carb by screwing in the needle assembly, cleaned it out, sang it a song but to no avail. its been removed to check for debris and i found nothing. i'm thinking that perhaps the float might be stuck but then again, i'm new to working with carbs.

you were dead on. i switched out the needle assembly and now she runs like a dream. thanks for your help, you probably saved me at lease $300 in shop/towing fees