The ports on the Italy ST are better matched to the case and have more detail in them. The transfer and boost ports are lower than on the China STs. I had thought they were the same also until I picked up 4 used st 45s that were made in Italy. Two have the "S" on the side and the other two have 45 where the "S" is. stock so far we saw 14,000 open exhaust with a APC 10x7 on one of the engines.