i got a replacement 700 r4 from a mid 80s pick up swapped the kickdown cable mounts but the speed cable is diff on the new tranny so i wont be able to hook it up also the old one in my 700 r4 is broken i believe i can replace it but idk what part its called but my question is is it possible to bypass this and maybe hook up a after-market gag maybe

the new tranny was electric and my old was mechanical

 

nevermind found my answer just gonna replace the speedometer gear assembly