Chevrolet: timing, 1977 chevy malibu, chevy malibu

Question
1977 chevy malibu classic 350. cant get the timing set, put new timing chain on i lined up timing marks on cam and crank, pulled # 1 plug made sure piston was TDC but it still wont stay timed maybe theres a problem with the distributor?can you help me out.

Answer
Dusten ;
 Hea - well first off I hope the cam sprocket and chain were put in right. ok than when you put the dist back in you must have the no# 1 cyld  up and on tdc. with the timeing mark on the tdc spot. ok than you must  drop in the dist . with the rotor on the no# 1 plug position.  than you will let it drop in and if it will not fall all the way hold the dist so it can not pop back up and out and have someone tap the key - it will soon fall into the slot on the oil pump and than snug the dist down and replace the rotor,cap and fire it up than with the vacume line off the dist. and pluged. if you have one- do the timeing - and re check the plug wires fire order. ok  if it is off by one tooth it will cause you all kinds of hell....