6605588 kit was developed for holes that were previously repaired and failed.
The 6605553, 6605141 and 6605141E kits can only repair holes as large as .640 inches or 16.3mm.
The Triple oversized 6605588 kit will repair failed inserts as large as .720 inches and
works in conjunction with the above kits by installing a special insert that will accept the
66151459, 66151407 and 66151457 inserts.
The kit was originally designed for fleet dealers that had vehicles with 200+ plus miles
and already having an insert that failed. These dealers felt because of the mileage and
age of the vehicle they were opting to scrap the entire vehicle for 1 spark plug hole, due
to not wanting to invest the expense of replacing 1 or both heads. The 6605588 can now
repair these vehicles by putting an insert inside an insert.
Instructions 6605588 click here.