performance chip for 1991 s-15 jimmy

i have a freind who has a 1990 gmc jimmy. he has an automatic tranny and it got wrecked. he has put a performance chip in his computer and wanted to sell it to me. does anyone know if it is possilbe to us the chip because i have a 5 speed tranny. i want to put a chip into it but i can not find one for a 1991 with a 5 speed. does anyone know where i can find one.