Lots of information and mis-information posted here so I will try to clear up the situation on the TA link chain with billet gears.
I probably hold the record for the most broken timing chains in a turbo V-6. I have broken all the brands of double roller chains, and some than once, and also so-called "performance" link chain sets.
When I discussed this with Mike at TA a few years ago, he said try the new-type link chain he developed for the V-8 Buicks. I declined since the V-6 version had a cast cam gear, and I had already trashed 2 of those?
After about 9 months of discussion and searching, he invested in a run of billet cam gears for the V-6 link chain.
Early in the sales of the new TA link sets, it was found in some builds the chain was extremely tight due the normal block production tolerances.
The solution was to find a link chain set which would fit to accommodate blocks and builds with different final tolerances . Tooling for another cam gear is very expensive, so using a different link chain offered an excellent solution.
This situation is clearly experienced in this thread as some sets fit fine, others do not?
My research with other companies like Cloyes has also illustrated the chains will stretch very little, the resultant play after use in a timing chain is mainly gear wear.
When ordering, TA will do their best to supply the proper chain set, but will exchange the chain if needed.