No one at this time makes a direct bolt on application for our 3.1 Rodeos. Calmini was thinking about it at one point in time, but dropped it due to lack of interest. If you're willing to get some custom work done, the 2.8 headers from an s-10 (I believe) will work - one side fits the other side will have to be bent a little. Give Matt at Indy4x a call or email, he should be able to set you straight.

Matt - 92 Rodeo LS (sorta)
tell tail signs
It's no fun to climb the ladder when the rungs on the ladder are bent - The Recipe