Re: Mixed 390 Rods?
ford has used both of those rods used in either of the 390 or the 428. The rods should be the same length eyelet to eyelet, so it doesn't matter if it has different castings, as long as they have been balanced all the same you'll be fine. If one set is considerably heavyer than the other set then they are beefed up for performance, then you might want a matching set. Your 2U is a 3.78 stroked crank used for the 390 406 427.