What gas engine bellhousings will interchange with a 6.9 7.3 ford diesel?

The bellhousing on a Ford 6.9L and 7.3L IDI diesel engine is not interchangeable with gasoline engine bellhousings. These diesel engines have a different bolt pattern and overall configuration compared to Ford gasoline engines of the same era (like the 300, 302, 351, etc.). You'll need a bellhousing specifically designed for the 6.9L or 7.3L IDI diesel. Trying to adapt a gas engine bellhousing will require significant and likely impractical modification.