Indeed, the O-series was used in montegos and maestros in carb, turbo and EFI form (I think the turbos were all carb models). It was also used in nasp form in a few very early 800's!

hi i seem to recall a standard 2300s being pretty nippy without having to spend too much dosh .Reliable so long as some coolant system probs sorted + daft cam bolts being sorted out. 2300 more lively revving than a 2600 so more scope .prefer v8s myselfe but they are hardly problem free + do cost money to upgrade