I have a 1978 euro 635 rust bucket with a good drive train & I am wanting to put it in my 1983, 633 U.S. car. What needs to be done to make this happen?They both have some different electronics & different fuel injection.Please help me out I am at a stand still on the project.I also need to know how to plug the speedo hole on the transmission from the 78 euro car I want to put it in my 83 but it has a pickup for the speedo on the diff.I just need a some good information on this swap.

I have the very same project. I have a 79 635 rustbucket and a 87 635. The car has been at my mechanics for the past 2 years as it is not high on the priority list.

Both 6ers utilize different motor mounts so one had to be fabricated to mount the M90 into the 87 body. Now, with that being said and done, the new motor mount then blocked the path for my Hartge headers. To clear it, the motor mount was then taken out, gussetted and the interfering part milled off. Apparently, this is area is unused as it no longer connects to the motor.

Regarding the tranny, it would have been nice to use my old CR 5 spd, but the 5 spd in the 87 has a much bigger case and seems to be much beefier. Also, there is no need to worry about a custom driveshaft.

And so, that is where my car stands, or sits.