My 82 Delta 88 has a 307 engine with a TH 250C trans with Lock up , the 250 also has the adjustable band screw on the outside of trans . No issues so far with the 250 , but from what i read on line if someday have issues do not put any more money into it . The TH250C could be replaced with a TH350 with no lock up . I am not sure the 250 would do another long steep hill climb road trip , so thinking about changing it out . What do i need to know for a swap ?