hello, how can you tell if the timming chain needs replaced, in a 350 small block? I have it appart right now.

If the chain it loose it needs replacing. Check the teeth of the timing gears if they are really sharp or pointy then they need replaced. Check the metal on the chain, see if it is pitted or worn.
If you already have it apart I would probably just change it. It won't cost much and it might save you some headache in the future.

thanks for the info : yvon

If the engine isn't apart, they usually make noise of loose.

hello, I change my timming chain and gears, what I did to change it I turned the mortor so the 2 mark line up, the top gear the mark is on the bottom and the bottom gear its at the top, this is what I learned online. Now what I want to know is to put new plug wires,do I have to turn the mortor so the rotor button lines up with the #1 piston? and where would be # 1 on my timmer cap? And also from #1 going clockwise?.Please I dont want an answer from (RASMATAZ) hes way too rude and he didnt make scence!( Im new at this machanic work so bare with me THANKS.