s14 chasis, s13 redtop and transmission, what do i need?

[PuffnPush]

do i use the redtop engine harness and ecu?? what will i need to change?

[kpodj61240]

Yes you will use the ecu and harness off of the SR. You still need your harness off the ka as well, send both of those harnesses to JGY or Wiring Specialties. I sent mine to JGY ( JGYcustoms.com ). It cost me $200. Or if you trust yourself you could do it on your own. Other things that will make life easier are use the S14 temp sensor (2 wire one). The S13 temp sensor will read hot on your S14 gauge cluster (kept me up for days). You need your S14 speed sensor as well, the S13 speed sensor will read double on your speedo. Email me if you have anymore question's I will be glad to help! [email protected]