Does anyone know if a 91 B18A cable trans will mount into a a 98 DC shell with no modifications? Would I use DA mounts on the DC shell?

 

The DA mount would be needed for the passenger side, and you’d have to do a hydro to cable conversion... It would make more sense or (at the very least) be cheaper to open the cases up and swap over the internals into your hydro case, provided it is in fact a YS1 LS transmission and not a jdm or other foreign one with the slightly smaller shafts. I recently swapped s4c internals into one of my ys1 cases and it’s fairly easy. I also put the old ys1 internals into the s4c case for safe keeping (it’s a direct swap either way with no modding needed), as I’ve got to replace the synchros on that gearset sooner or later.