The 602 is one of the old "new generation" iron block/alloy head engines. Actually the normally aspirated 602 produces quite a bit more power than the normally aspirated 617, and the turbo versions of both were about the same in output.

I've seen two HP figures for the n.a. 3.0 liter 5 cylinder 617: 77bhp and 83bhp.

The n.a. 2.5 liter 5 cylinder 602 was rated 93bhp

The turbocharged version of the 617 was rated 120bhp, while the turboed 602 was 121bhp.

The 602 appears to be a long lasting engine, with only a minor problem with the hydraulic lifters. It seems that they either start to go bad, or some o-rings in the oil filter housing dry out... in both cases, intermittent valve noise results. It is just an annoyance, though it probably does affect maximum performance.

Overall it is lighter, quieter, more fuel efficient, cleaner, and has a better inherent HP-to-displacement ratio. Its just technology and evolution.

However, it is not as ultimately robust as the monster 617. Care must be taken not to overheat a 602 because the heads are apparently quick to crack under such conditions.

-Joe