How's it going everyone. I decided to rid my IROC of its L98 and install an LSX engine/tranny. So my question is, has anyone been able to successfully modify to use their mech or electric stock speedometer?

 

depends on your setup. If you use the 700R4, you can maintain the mechanical speedo. If you go to an aftermarket T56 Magnum, you can maintain the mechanical speedo. If you go to a 4L60E, you can get a Dakota Digital conversion box to run the mechanical speedo, or open up the trans and if necessary (I'm not real familiar with 4L60Es), swap the output shaft for a 700R4 output shaft and tailshaft to use the mechanical drive. In all of those cases, you can use the output from the stock VSS to feed the speed signal to the ECU, provided you modify the tune for the right PPS. In the case of the T56 Magnum, that has both mechanical and electronic speedo outputs, so you could run a VSS and a cable right on the trans.

 

If whatever your trans is doesnt have a mechanical output, a driver box (Cable-X) is the simplest solution

 

I used the Cable-X to drive the mechanical speedometer on my LS1/4L60E conversion in my '88 Iroc. I outlined it in post 55 of my build thread. https://www.thirdgen.org/forums/ltx-...2-trans-2.html

 

Looks like this one is a winner!!!
http://www.dakotadigital.com/index.c...rod/prd886.htm

Does the Cable-X have a maximum of 70 mph?
http://www.abbott-tach.com/orderpage.htm

 

No. You're looking at tachographs. Scroll down.

 

Cable-X-3012-GCable-X with Frequency Convertor (GM Snap-on)

 

Or http://www.t56cablespeedometer.com/

 

Staying with automatic tranny. If there's one thing that I love, its doing a stationary burnout.

 

But in this case of using my current 700R4, I would still run into the problem of using a TV cable since the LS6 throttlebody doesnt have those provisions. So with that said, what options do I have in regards to the TV cable being a necessity? If I can save a few hundred bucks, I would. But if there is no other options, Then I would have to buy a 4L65-E.

 

I didn't know Dakota Digital had this unit. I actually like it better than the Cable-X. It will be much easier to set up since it's driven by GPS. I wish this was out there when I was buying parts for my swap...

 

I believe someone makes a tv bracket for ls tb's. ws6store or something might? I cant recall the exact place

 

Roger that OrrRocZ. Will investigate. Thank you. Either way, I would still need to beef up the 700r4 right?

 

If you plan on beatin on it and want it to live then yes. That said my 4l60 is at 127k miles and living behind a ls1 bolt on car and i have seen a few beat on sessions