Timing Chain replacement on Northstar
 

I just finished doing Time Serts on my N* 4.6 (went well) now I am trying to get the timing chains back on and have a little problem. I have lined up all the timing marks on the various gears and now am trying to put the chain on. the problem is there is some slack in the chain and I don't know where it should occure. I had the heads off but never removed either the cams or the cam sprockets and the primary crank chain was never off. I know this shouldn't be difficult but I don't want to screw it up and damage something. I have the shop manual for the engine but don't feel that the instructions there are that good. Is there better reference for this task?