Here's a link for, bay into bug conversion.
https://m.vwheritage.com/productDetails.cfm?iItemID=152929
Once found a step by step with pictures, but can't find again. Seem to remember a 4 speed fits but a 5 speed needs the pan cutting, both will need an IRS conversion
Planning on trying the Audi box in my rail build, but don't hold your breath as things have slowed lately
Ttfn Glenn