having major problem

im timing my 350 i just built its at top dead center won't start i take the distributor and move it a tooth advanced and it starts but runs like crap. what could this be before i take the front of the motor apart and make sure my cam mark is ok.
thank you

Sounds almost like the same problem im having. Check my post "Now Whats Wrong?" Worth a shot. I got alot of good advice in this post.