I do not know why you would do this. I have had much experience with both the 617's and the 60x's and they each are wonderful in their own right. In the end, I prefer the 60x's as I believe that they were a significant advancement in fuel economy and overall design over the 617's. Also, I find these extremely durable, I have a 601 with 320+ kmi which is original and just purrs.

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Jovan

'84 (11/83) 190D 2.2 5-Speed; Silver/Blue; Motor No. 00354, 402k mi (340+kmi mine)

'89 Porsche 911 Turbo Coupe; Black/Black; 53kmi
'05 BMW 530i 6-Speed; 302kmi
'19 Range Rover; 30kmi