I have a 98 3.0 ranger is there a E85 flex fuel kit for them

 

No, and it would be expensive to convert a 1998-2000 Ranger, the Fuel Type sensor was $650 if you can still find them, and then the Flex Fuel PCM(computer) and 6 new injectors, which wouldn't that hard to find

2001-2003 didn't use the fuel type sensor so you would just need the PCM and injectors
And no, can't uses 2001-2003 computer in a 1998

Sell the 1998 gas only and buy a Flex fuel model