My cam isnt stock and my motor is a 355

" run the 305 originally ". You didn't state what you had in it I assumed it was the same. I know you have an edlebrock, what cfm? Once you set the timing with we both posted, lets look at the carb.

The carb is an edelbrock 1406 elec choke vac secondaries 600 cfm
The distributor used to run a 305, now it is on a 355 and the cam in it is comp hi-energy 268H f/t

I say you are under carb'ed.

I am noticing that my timing is advancing right off of idle. It is set at 10* and as soon as i move the throttle it advances right away and at about 1200 rpm the knocking occurs. seems to be advancing about 8 degrees. Also, at idle it dances around a little, toward advance though not retard. but when i rev it past 2000 rpm it seems as though the advance slows down such that the knocking goes away. I have my heaviest springs in the distributor right now but it seems that in the beginning it advances too much too soon but then it slows down between 2000 to 3500 rpm

I am waiting for the engine to cool down and im going to put the weights and center plate in i got from the kit, i am told that the weights from the kit are lighter than the stock ones so hopefully that will stop the advance from happening right off of idle

maybe my springs arent tight enough?? people talk about pre-load and tension, i just put mine on the posts, it seemed tight...

im going to post a video of the engine running on youtube

the audio quality is a little bad when i rev the engine but hopefully you can get the idea

Sounds like exhaust flutter even with headers Looks like an 84?. Mechanical fuel pump in a G body Olds (well at least it's an olds). Take off the KN air filter arrangement, does it make any difference? This isn't ping nor what I can tell mechanical issue, other than it follows rpm. Could also be a belt or accessory, can you pin point the noise closer?

The video doesnt do justice, it isnt very loud to begin with. the sound i hear sounds too big to be the rockers or lifters and too small to be something in the bottem end. I cant run vacuum advance because it makes it worse. what if! (god forbid) my timing marks are not correct, should i be able to back the timing down till the noise goes away?

Is the fan rubbing the shroud?