My engine&tranny are out (vortec-tbi on-deck), and I'm contemplating a 4l60e because I can snag one from pick-a-part for $125 (the only 700r4's around are $500 used). My 700r4 will soon need a rebuild, so I'd like to take it out of commission and rebuild it before it gets to that point.

Only major problem I see is the lack of VSS in my np241c t-case. The 90-91 np241's have a 2pulse VSS (or 4??), but I'd like to keep my mechanical speedo and drill&tap a new hole for VSS if it's possible...

I have the PCM/harness from a '96 suburban (got it with a vortec 5.7 that's about to get a GMPP tbi intake that arrived from jegs today). I'm pretty sure the TPS and tach signal off the TBI coil can be wired up to the 96 PCM without any trouble, and the 4l60e's have a vss on the tranny shaft. The only missing component I'm aware of is the 40 pulse vss.

On pirate4x4, I found a thread where some guy added a VSS to an atlas transfer case, and I'm wondering if this is something that can be done next to the '89 mechanical speedometer gear.

Is there something I'm missing, or can I use a 96 PCM to run a 4l60e/4l80e in my '89 tbi?

 

You can pick up a VSS add-on box that will allow you to retain your factory cluster and get an electric signal for the PCM.

Are you getting the PCM reprogrammed to run your TBI engine?

 

I was going to splice the TPS and TCC brake switch to feed both ECMs, and then run tach & VSS to the new pcm.

Got off the phone with pick-a-part and they say they don't have any good 60e's (they had several before x-mas). There are 2 TH400's, but I'm pretty sure the output spline count and length differs on those (and no OD).

Perhaps I'll just run my old 700r4 into the ground. I don't have a warm fuzzy feeling about it lasting through the winter, but maybe the new TC I have will buy some time and I'll get lucky. I can't justify $500 for a used tranny that is probably as close to needing a rebuild as mine.