I've heard ECS is the best & most accurate, but have no personal experience on E carpets.
I generally use ACC on A- and B-bodies.
I got a carpet for a 70 Challenger about 2 years ago from Legendary which came in a box also marked ACC. Total garbage. Thinner material and padding; along with a crapy fit. The underside padding was also glued on folded in half! I bought the same carpet from them 25 years ago and it was just like my original. The lady I spoke to from Legendary says ACC supplies them with the carpet which is now made in China. Surprise Surprise!
