i have a holley 3310-1 780 CFM carb that i am considering rebuilding. if the directions are relitively clear, i think i would be fine at it, although i have never attempted it before. are any specialty tools required? i have all of the basics, but nothing too crazy. final question, how much would it cost to get it rebuilt if i were to start and figure out that i am not experienced enough to do it?

Not at all.

A Holley carb is about one of the simplest things there is. It's really not much of a challenge at all.

I would suggest either smearing a VERY THING layer of grease on the gaskets, or soaking them in motor oil and wiping the excess off, so that it will be easy to take back apart for fine-tuning once you get it installed and operating.

what actually determines when a carb needs to be rebuilt? old leaky gaskets or something like that?

Thats part of it. I'm sure there is more. We should get more info pretty soon

If you aren't sure, take pictures and post them - mainly the metering blocks and fuel bowls. We can tell you what kind of shape those parts are in, like if they require dipped, or just sprayed out with some carb cleaner.

A 4150/4160 Holley is about as straight-forward as carb rebuilds get though. As long as you pay attention when you take it apart and take your time you should be ok.

As for what Sofa said about coating the gaskets with grease/oil so they come back apart later, you can buy a Holley rebuild kit with the blue reusable fuel bowl and metering block/plate gaskets that don't require anything added to them. They are already a good non-stick gasket, I like them.

i always spray the blue reuseable gaskets with WD-40 so they come apart easier in the future

Yes, they are among the easier things to rebuild. Holley parts are a must though. It seems as though the off shelf brands aren't as "perfectly matched" as the Holley branded ones. The only tough thing about rebuilding these is getting everything tuned after rebuilding which shouldn't be too difficult.