Let me know how it goes with your new tuner. If it has the mds shut off I will probably pick that one up. I have been.looking into a Cai. but the tuner is a bit more important since I hate the mds. so.far I got some new shocks, level, wheels, tires , pads, rotors, 3.92's and the magnaflow welded on and the truck.is great except for the mds.
I've only just recently loaded a 93 performance tune. It woke the truck up significantly.
I see that it has a tow tune, an 87 tune, mds & trans shift points I believe I heard were also avail. I'll do some more tinkering and report back.
It was definitely worth the $$$ and goes well with a new exhaust and full fluid changes to Amsoil. I also have the Mag-Hytech rear diff cover in place. My next upgrade will be the brakes and suspension. Good luck.