They’re not. Completely different bodies. (‘68 laSabre interchanges with ‘68 Electra and Wildcat. ‘69 leSabre interchanges with ‘69 ‘Cat and Electra). Patrick
67 and 68 are closer, but I'm not sure if they fully interchange. But those two years share essentially the same body style.
Guess that 67 - 68 share some parts, and 69 - 70 share some front clip parts. But 68 to 69 for large cars, likely very little. Bolts, washers, etc. This is '69 full size. A lot of it probably works on 70, but not 68.