Saw this on Diesel Toys website. Not sure what others know about R2.8. Thought I would share. Link says 4BT conversions but has R2.8 perspective.
Cummins R2.8 & 4BT | Diesel Toys® |TOYOTA DIESEL CONVERSION EXPERTS
Cummins R2.8 & 4BT | Diesel Toys® |TOYOTA DIESEL CONVERSION EXPERTS