My mate Craig has a Courtenay 1.6 8v Nova GSi turbo. Lush little car. There are some pics on Novaload somewhere. He has since pulled the engine out when rebuilding the body. He thinks he may be able to attempt his own conversion. But in hinesight he was glad he took it to Courtenay for the conversion as they did an amazing job.
One thing I will say is have a full engine rebuild. Not neccesarily with reinforced conrods etc. But maybe some new bolts and a crank regrind.