Little ol' 170, with a turbo?

The 170 is a great choice for turbo. It has the same head airflow as the 225 but smaller displacement. The 170 also has a much much higher rpm potential if you are willing to use it. You should definately contact charlieS he has had a turbo 170 for more than 30 years. If you try the J-pipe style of turbo mount remember that everything in the 170 is 1 inch closer to the k member which might make it a tighter fit.

If it is a manual trans car you should also read up on 5 speed manual trans swaps. That would allow more gear and still give a decent cruise rpm.