Slack in new timing chain

So I've had the timing chain and timing all set on my 360 for a little while now, the heads are all torqued on and I'm putting the rocker arms together. But I keep seeing the timing chain and I've come to the conclusion that there is too much slack, I didn't measure it but both sides can easily be moved back and forth about a 3/4 inch, and it's brand new! There has been a lot of block work, so I'm thinking I need a slightly shorter timing chain because the crank needed some work. Can I get a shorter timing chain easily or are they hard to find? And can I change it without messing up the timing? Or is a little slack okay? It's only slightly less slack than the old timing chain that came off had.
Send the Sa gear BS back and order a Cloyes set. common problem with the crap on the market today. tensioners are ok with the right combo,but other combos eat them up putting lots of plastic thru the pump.