Hi Ron from Holland, your english is better than most Australians who own a B210.

If you can find a SR20DET 200sx, using it's engine and gearbox would be the best way, if that is a legal swap in your country.

The s13 CA18DET gearbox bellhousing is slightly smaller than the SR20det gearbox bellhousing. But the gearbox is the same. Except the CA18 one has a slightly different 5th gear.

We shorten the diff housing from bigger cars in Australia, but in Europe with the tax laws, you don't have many to choose from.

Good Luck with your conversion.