Salvage yard tells me the interchange book shows '05-'06 3.5's are not compatible with '07 and up.Any techs out there know what the difference is or if just some minor things need swapped from an '05 engine to an '07 engine.I have a chance to buy a known good '07(cheap) to put in an '05 300.

Some of those engines were year specific due to the cam gears. If you had the wrong year motor it would hit rev limiter at like 1000 r's. Call your dealer, or since you are in marion, call Button Dodge parts ask for Larry, tell him Nate told you to call give him your vin and see if an 07 will interchange. He'll know why, because he's dealt with it before.

I'm Parts Manager at Mike Anderson Dodge.The part#'s for the heads,cams,and cam sprockets are the same from 05 to 07.Short block part#'s are different though.