Bob, ICC’s make their big push in US sprint kart racing at the national level around 2002 when people grew tired of getting their asses kicked by SwedeTech Hondas. At the time, the mantra was they could be run box-stock, on pump gas and it would put and end to $5000 engines. It all turned out to be a load of crap. Engine builders quickly found ways to make more power so you still needed built engines, they ran race gas and they ended up being more than $5000. And in the end SwedeTech dominated ICC just as they did moto.
As I recall Paul Leary had some good Pavesis, Italian Motors were good TMs. Swetech started out with CRS, then did Pavesis, then Maxter and finally TMs.