If you change motors the simplist is a 300d na. It should bolt right up to your tranny and the oil filter and battery will be in the correct place for you. I did one of these and it makes the car much more drivable with the extra cylinder especially with the automatic transmission.

Good luck with it.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.