Maybe take out the lower bolt and see if it will thread in and seat in the position of the upper bolt. If so, Bob's your uncle. You have the proper bolt to match either at a dealership or with the appropriate overall length, shank length, thread pitch, and grade from your hardware store of choice.

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson