without the cable, in the atx, only issue you will have is you can start it even if it's in drive or reverse. no biggie, just be cautious

for the clutch safety switch, same thing. you will be able to start it in gear. again, just be cautious

if you swap engine harness, body harness, the whole dash and ignition, then you won't have to worry about either of these small issues.
if you go this route, don't forget to swap the vin plates on the dash, lol

i'll gather some pics and send them your way. pm me your email