I have a '98 f-150 4.6 4x2, that has an 4R70W 4sp. auto. It has been giving signs that it is getting weaker as time goes on. Shifts hard from 3rd - 2nd under load, overdrive slips a little. The truck still runs but I do not want it breaking down in the middle of nowhere with me thinking...should have swapped them before now. SO, I have found one reaasonably priced with decent miles on it, but what do I do with the core? Like I said it runs, not like it's exploded or anything. The dealership told me that they changed the bolt pattern and gears ratios etc from '98-'01 and that this particualr tranny was a 1 year only trans.. And there were about 20 different 4R70W all together and VERY few will interchange. I would think that being as how these specific 4R70W trannies were only made for one year, and that this one isn't totaly screwed, that it would be a good candidate for a rebuild. I have called some places and they say yeah we'll take it and put it in out scrap pile for free....I bet you would. I do not want to scrap it, there has got to be a core place to take it to. Any suggestions?