Great forum...I have been lurking around for a while and have run into a problem I hope to get some help with.

Bought what I thought was an 03" ML320....flawless car minus the bad engine.

Figured I would get a jump on things and ordered a low mileage motor. Had the car and motor delivered to my mechanic and discovered the car is an ML350.

I called the dealer with the vehicle and donor motor vin # to order parts and the dealer said it was an exact fit...timing covers, oil pans etc...were the same . I gave hime the vin # to the ML350 but told him it was a ML320.

Any way, now I'm wondering if the ML320 compatible motor will work in the 350...I did some research and have found they are virtually identical motors except for the injectors and displacement. Im thinking I may have to flash the ECM but not sure. Thinking the computers are probably the same considering the injectors are different...bigger injectors on the 350 motor = more sray...I think the spray pulse is the same?

I can get the exact fit engine but trying to save a little time and $$ since this motor is a clean low mileage unit for 1/3 of the cost.

any help or insight is greatly appreciated