[spuggy]

It's often cheaper to drop in a stock 930 motor than lots of custom motor work.

They're fairly simple to wire in, and the 930 mates straight up to a 915. There's a Sachs competition pressure plate rated @ 350 ft/lbs which will deal with it just fine. (The Power Clutch is borderline, at best).

A stock US 3.3 930 (265 HP) or a RoW one (300 HP) both make enough torque to turn a mag-case 915 into soap. But a later 915 will live if you beef it intelligently and don't just mash the loud pedal at really low RPMs...

The big advantage of the 930 approach is when you dial in the suspension, brakes, tranny etc. get bored with 300HP and decide you want to add another 50, 100, 150HP - that particular route is relatively cheap, easy and well-travelled - to say nothing of being mostly bolt-ons...

Paradoxically, most 400-500HP 930's are easier to drive than the stock 930. With good headers and turbos, you lose the turbo lag and the sledgehammer-to-the-chest effect and end up with a tractable car instead...