TonyS

Read the web link at the bottom, there is lots of useful fault diagnosys. Also if you look around the site there are articles about dropping in a B230FT or similar.

It would be definately alot easier to do this than mod the current engine. Apparently the right engine fits straight in with manifold and turbo, you just need a custom down pipe.

Rear axle - you need to think about straightening and strengthening this.

Front suspension - For a start replace the top bushes and spring mounts, and pretty much every other bush you can find, and shocks of course (Monroe gas are good value). Having said that you may need to consider something special for for brakes etc. I intend to do the Turbo drop-in then see how the brakes cope.

Steering rack and master cyclinder need heat shielding for Right hand drive.

Can't think what the knocking sound would be. Could the suspension be bent enough for the wheel to slip on slow corners, or touch the anti-roll bar?