[racer]

Sounds like a lengthly project.. I don't know all the dimensions, but I imaging a bit of fabrication for engine and trans mounts are an issue.. what about axles? Does the Boxster motor mate to anything but the newer trans? then running shift rods/cables.

As mentioned, lots of electrical work and perhaps even more-so for the 2.7 since its e-gas vs the 2.5s cable.

Then mounting radiator lines (i'm sure the SBC crowd has done this already though).. capping off powesteering pumps?

How does the Boxster motot compare in size to the 911/914 motors? how much HEAVIER will the car be with the new motors/radiators etc.

What about mufflers/exhaust? is there room for something modern emissions compliant under the 914?

No HP conversion/upgrade for the 914 is cheap. If you want something straightforward, then a big 4 is a the first choice.. then a 911 motor (but then you need oil tanks, engine motor mounts, etc etc.. all well documented.) plus the more hp, the more brakes, tires, (flares?) and suspension you will need. It becomes such a nasty slope!