200tdi conversion

Hi,
Am looking to bolt 200Tdi disco engine to old 2.5NA clutch housing - but the 4 bolts on the ladder frame are missing on the 2.5NA. Is it OK to bolt up and forget the 4 bolts or do I have to drill and tap the old disco cover to fit - does it matter - it would be easier to just bolt up the 2.5NA cover plate?
Thanks

there are some exstensive guides on here search and all your answers will be found

i just swapped over my flywheel housings put the old one on the tdi , easy job and worth doing rear oil seal at same time.

Ditto.

I kept the Disco bell housing and put Steve Parkers bolts in

Steve Parker Land Rover Servicing, Land Rover Spares and Repairs

Pretty simple job and the logic makes sense. The advantage I saw in keeping the disco bell housing was the drain plug (not fitted in yours or the TD) which allows you to drain the bell housing and use a flywheel locking tool should you need to redo the timing belt.