Will a Cis system from '82 work on a '79 motor?
 

I guess the real question is, can I use the '79 wiring harness? or, what else is required for install?

Thanks, Jack.

More clarifacation:
I have a '79 3.0 with carbs, I don't like the carbs and want to install CIS. I have access to a free '82 cis system and need to know if I can use the '79 engine wiring harness or is it different in '82.
Also, is the computer box under the seat the same or different?

Unless the 82 system is from a ROW car, the intake runners will be too small. Also the Lambda brain and wire harness is different because the 82 uses a frequency valve.

I would get the correct 78-79 system.

What computer box? Those are only on Motronic (after 84).

Thanks Vinny,
I knew there was something different, hadn't thought about the intake runners though.

The later SC's still has CIS but it incorporated an oxygen sensor and a little computer that controlled a frequency valve to alter the control pressure and thus the mixture.
-Chris

I don't think your going to like the swap. You won't get the throttle response out of the cis that you do out of those carbs, if the carbs work properly that is. If you going back to FI i would go for the motronic unit, not the CIS.

Can I put a motronic FI from a 3.2 on it? That would be ideal.

In short, no. But you could use Motronic intake runners from a 3.2 with a Tbitz EFI conversion

http://forums.pelicanparts.com/porsche-911-technical-forum/372213-motronic-3-2-3-0-sc.html?highlight=cis+motronic
http://www.bitzracing.com/gallery/Mike_79_911SC.html