Hi, sorry maybe being a bit of a girl here so forgive me if my answer isn't exactly what you are a asking, it's a 2.5 standard V6 with no mods, only a K & N filter ( not the kit ), I think it's the M20 but engines are not my expertise, I have tried to keep it as original as I can, as close to how it was when it was built. To be perfectly honest the engine has always run extremely well, I had it tuned about a year a go but not for extra power just to make sure everything was doing its job properly. Regards Paula