they made 25000 SRT4s and tens of thousands more turbo PT cruisers all the way to 2009. its a much better motor (parts wise) than a turbo III.

The SRT4 engine weighs more than you think. closer to 350 with manifolds/accessories and it is tall. Then you also need intercooler, piping, etc... There are a couple people working on A-body swaps right now, i kicked it around half halfheartedly as well. The issue that i can see is that a good street able e85/stage3 turbo will do 400ft and 400HP. you can do that with a MILD v8 all day. and not have as much torque right off idle to 2500. 3000 on up it will run great.

In the end it would be a giant PITA. cool but a pain. I'm going 5.7 hemi as soon as i can stand to have my car out of commission... which is why the engine is still on the stand for 4 years.