Can anyone provide me with the proper method for determining if a timing chain has too much slack? It's a Gen VI BBC with one of the Summit-brand billet double roller chains on it. It was a new chain that was run for about 30 hours. I had to have a line-hone done on the block, and I want to make sure I don't need to go with an undersize chain.

Seems like I read somewhere that you are supposed to rotate the cam gear in one direction to take all the slack out of one side, then push in on the opposite side of the chain. If this is correct, then what is the cutoff on deflection here? I did this last night and estimate that I saw about 1/4 inch of deflection, but I need to get a machinist's rule on there to measure it for sure.

I have also seen some people checking it by squeezing the chain together, but this seems less precise.

I tried turning the cam gear both ways against the crank gear by hand, and really couldn't move it much by hand. I had to use a screwdriver to (gently) pry it to get the slack on the one side.

I realize most chains stretch a certain amount when they have been run, then stay that way for a while, so this one should be "broken in".

Looking forward to hearing anyone's thoughts on this, especially the pro's who browse the site. Sure not looking forward to spending any more money on this thing, but want to make it right!

Thanks in advance.