I'll be doing a R&P swap in my cousin's other TA22 later this year, working from a jig I've made.

Last time I did it, and next time are made as follows...

1. KE70 crossmember
2. Engine mounts removed
3. Custom fabbed ends to bolt up to the narrower chassis of the TA22, retaining factory LCA height and position front to rear.
4. Engine mounts re-jigged and welded in to factory TA22 position with gussets/extra strength (both his cars run T engines)

For A series in TA22, you might be able to use an AE71 crossmember and not remove engine mounts. Doing point number 3 as listed above, then test fitting in car to see if engine drops in with clearance similar to AE71/AE86.

Can you weld? It is a time consuming job, but if you can DIY I can give pointers on how to go about it.