C5DA-6394-A, D20A-6394-AA, D5DA-6394-AB.
The original 260 bellhousing has 5 bolts (where it is bolted to the block) and is not compatible with later larger capacity blocks (except for the very rare 5 bolt 289 blocks).
A larger front bearing retainer is also required, WT170-6G (originally C5AZ-7050-J).
Unfortunately, the 4 original gearbox mounting holes in the rear of the above bellhousings do NOT match those of the HEH-E gearbox. If you have a later HEH-B gearbox then you are in luck and you can ignore the next part.
The bellhousing needs to be correctly aligned with the HEH-E gearbox, preferably by the larger front bearing retainer and then 4 pilot holes drilled.
Next, 4 pieces of round aluminium bar are temporarily held in position by nuts and bolts in the pilot holes.
The 4 aluminium pieces are then TIG welded to the bellhousing, then later drilled and tapped for the 4 original 7/16 inch UNC gearbox securing bolts.
The various stages are shown in the photos below.
**Please note that the rear of the aluminium bellhousing is thin and weak.
It is NOT advisable to drill the rear of the bellhousing and use nuts and bolts to secure it to the gearbox, especially with a modified engine.
If the bellhousing material had been mild steel then this might have been a possible solution.
PS I almost forgot. You will also need an engine block plate/spacer plate like the one advertised in Classifieds!
Aluminium blocks in position-1
Aluminium blocks in position-2
Note the different bolt patterns of the HEH-E (narrow) and HEH-B (wide) gearboxes.
Aluminium blocks welded, drilled and tapped for 7/16 inch OEM bolts.
