http://www.turbobricks.com/mods.php?content=art0024

It's really not that difficult if you have access to a complete parts car.

There are two flavors for adding a turbo to a non-turbo car.

There's the "+t" - adding a turbo to a non-turbo motor. You leave the motor alone, and use various parts from a turbo car to put the turbo on it. A higher compression normally aspirated motor has some advantages - it's peppier off boost, will spool a turbo more quickly, all good for street driving. You'll just run into limitations on the fuel because of the high effective compression ration when you're pushing more air into the motor. So less potential peak HP.

Then there's the wholesale removal of the old drivetrain and replacing it with the turbo drivetrain. Main bit of oily work involved there is the replacement of the intermediate shaft. 700/900 series engines have the distributor at the back of the head, there's no room for that in a 200 series, so you need to add a block mounted distributor, but that needs a drive gear on the intermediate shaft. And they usually didn't bother grinding the gears into the shafts destined for 700/900 cars. Pop the plug out, you might have gotten lucky.
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'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)