[albanycobra]

I already said you can get an 8 Stack Windsor approved.Roaring Forties have everything you need to pass emissions and have had for years. RF have passed IM240 testing with a windsor 8stacked which is more difficult than adr37/01.

Here's what I learnt about emissions while getting my car licensed in 2013. Cat convertors have come along away in the last few years and secondary combustion happens in modern Cats, this process really cleans up your emissions. By using these Cats it allows motors with a bit of overlap to get through with a bit of tuning. Also modern programmable ecu's have a much higher resolution which gives much better control and closed loop operation.