The m116 and m117 blocks are identical externally except the m117 is 30mm taller than the m116 for a longer stroke. A 3.5 manual transmission would fit on a 4.5 no problem.

However, when MB changed the blocks on the m116 and m117's from cast iron to aluminum, they made the bellhousings MUCH smaller. An m116 aluminum-block engine has a noticably smaller bellhousing. Basically, for what it would cost for a 3.5's 4-speed manual and then what you'd need to adapt it to your aluminum-block engine, you can get a new, cheaper 5-speed tranny that isn't so rare and have the modifications done for that instead.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

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1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k