OK, it might work out if you can recreate as much as possible of the electronics from the Suburban. I yield totally to guys like lt1s10 who have years of shop experience on various carbs and ignition systems. In my former career I often would take some electronics from a surplus instrument and use it for another purpose just by taping off the leads I did not use so if I had this problem I would try to make the hookups as much like the setup the 350 came from and then ask for help from folks on this Forum. One note of comfort is that when the 2003-2004 Corvettes went to high mpg setups they also used a similar rear ratio with a 700R4 and a 350 so you won't be far off mechanically. Maybe you could even use the shop manual for the Suburban with the parts it used. Also as lt1s10 said, the tires on the Corvettes and the Suburban were pretty large so it may be worth checking the effect of whatever tires you have, but if you are willing to just use the OD occasionally it might work out OK. You may also have to mess around with the electric switch for the OD and maybe install a manual toggle switch unless the harness from the Surburban takes care of that. My 700R4 was converted to a hydraulic switch but as I recall the stock 700R4 uses an electric switch for the fourth gear OD, but if you manually shift from third to fourth and then down shift to third manually you may be OK, but without that switch you cannot leave it in fourth and expect it to downshift automatically unless there is an electric signal to the trans. Good Luck!

Don Shillady
Retired Scientist/teen rodder