[James Lamb]

Guys, I could use some help here. 1989 Suburban 1500 4 x 4, originally 6.2 diesel. Now 383 with mid range cam, Holley Sniper EFI.

The 700r4 has gone out (again). Will not lock up in overdrive. I know some folks really like these transmissions, but I have had nothing but bad luck with them. The current one is either the 4th or 5th rebuild in less than 200k miles. This one has 4000 miles on it, lock up solenoid was bad when I got the transmission back, I replaced, got another few hundred miles now not working again. I cannot face another 700r4. Seriously, I cast aluminum art on the side and I'm considering melting this damn thing down for metal.

SO, I found a reliable (I think) transmission shop that will swap in a 4L60e. Same dimensions, same overdrive ratio, should bolt right up, but I need aftermarket controller. Anyone done this? Holley strongly discourages splitting the TPS signal from the Sniper - US Shift Controller claims to have an adapter that splits and isolates the TPS signal so the one from Sniper can be used. Anyone tried this?

Also, I need either a GPS signal driven speedometer or the ~ $350 convertor box from US Shift to drive the OEM cable-driven speedometer. Any recommendations? The GPS gauges I have seen on-line are $$$$$$$.

Anything else I have not thought of? FYI I am a paleontologist, this is my field truck. My 4-wheeling consists of muddy roads/tracks, no rock crawling. I tow about 4-5000 lbs maybe once a year, so I think a 4L60e should be fine. I don't try to make 20-foot rooster tails of mud when I'm off-road in it, don't race it, typical on-road use is secondary state roads at around 55 mph, almost never interstate use. Yatta Yatta.

Thanks for helpful info.