An Alpina Z8 has a modified “standard” BMW 4.8L v8 which produces a little less power but more torque than the ///M S62 V8 - 375hp/383lbs-ft. instead of 394hp/363lbs-ft.
After BMW stopped producing the e39 M5 in 2003, BMW stopped offering the Z8 with the ///M s62 motor (which was shared with the e39 M5). They, instead, continued with an Alpina tuned car which had the different motor plus and an automatic tranny. It’s a nice looking car…one of the last by BMW, IMO…the car designer was Henrik Fisker who later moved on to Aston Martin in 2001…