Hey guys, i got a quick question concerning my LT1 swap. Do you need the wiring for under the dash from an LT1 car or will the wiring in my 92 RS work. I have the engine harness, but was wondering if i needed the dash harness too.

Thanks,
Kyle

no you don't need the under dash wiring as it would just make it that more difficult to splice it all together for your gauges and stuff.

Well, i got a guy doing the swap for me and he thinks i need it, how can i explain what to do to hook the enige harness to all my guages?

I would say that if the guy doing the swap can't figure out wiring from using diagrams from both year cars, have him stop the work and find someone else.

He hasn't seen any diagrams yet, hes a good guy and i'm fully confident he can do this swap. so please don't talk about my mechanic.

I read in another thread https://www.thirdgen.org/techbb2/sho...hreadid=325732 Where "Firebat" says its an easier job with the underdash harness, but i'm not sure, just looking for advice, not to get flamed.

Have your mechanic get a service manual for both cars (even a pair of Haynes manuals will do the trick). I was able to figure it out puting a 95 LT1 in a 91 TBI car pretty easily. The pulse output of the LT1 computer speedo wire was different than my guage cluster, so I had to get a device from Dakota Digital ($80) to fix it. Just leave the underdash alone except for what you need to tap into. My stock 91 Computer is even still hooked up (doesnt do anything though). Pull all of your idiot light bulbs unless you hook them up.

Dont know where you're getting the vss pulse is different, all of the 90-92 camaros use the same 4000 pulse / mile input that the LT1 pcm puts out.

Guess I got a bad piece of advice. Was told I needed it by a guy who did a swap on his third gen, so I took his word for it and put it in. Oh well, it happens. If u know anybody who really needs one, I guess I have a spare

If you plan on hooking up the cruise control you may want to keep it, see the stock thirdgen setups output a 4000 to the gauge, and a 2000 pulse / mi to the cruise box, so you could use the sgi5 to split the signal so the cruise module gets its 2k/mi

I actually do have plans to put the cruise back in this winter. Thanks.

so all you gotta do is splice a couple wires here and there?

also, could this be done witht eh motor in the car?