[Dave at Pelican Parts]

Boxster swap has been tried, but is not that easy. The engine is a little too wide to fit between the inner suspension mounting ears. This can be dealt with, but it's fiddly and challenging.

The V8 swaps have been common for decades. The small-block Chevy is a very popular swap.

Subaru swaps have become more popular in recent years. Mostly Imprezza WRX engines, but a few others as well.

Others have been done. Apparently a K20 Honda engine will fit. VW TDI four-cylinders for massive amounts of torque and great fuel economy. Nissan and Honda V6es. And so on.

Some of the above have also used Boxster transmissions. They're bigger and heavier than the 901 box, but can handle more torque. You may wind up losing at least some of the rear trunk space to use them. Subaru transmissions with the rear drive shaft output blocked off or locked out have also been used.

Lots of options. Some have been done more times and have "recipes" to follow; others require more engineering to be done. Places like Renegade Hybrids have a lot of knowledge of different swaps.

--DD