The surging your getting more than likely is due to over-fueling. The translator/LT1 sensor deal is nice, but lets get it working with what you have before making changes.
So... what cuases this, too high of a fuel pressure, chip issue, vacuum leak, air leak in the system(intercooler,hoses, etc)...
One way to check your chip/fueling is put the scanmaster on BL. Now drive the car and watch the BL numbers as you accel, decel, cruise, idle, etc... Look for numbers to be above and below 128. If all your numbers are skewed above 128.. its adding fuel to compensate.. or below..its rich...having to pull fuel out.
So... this is a place to start looking. I like all my cars to be completely smooth and transitionless into the alky. If it surges, bucks, coughs, spits, sputters, etc.. it needs tuning.
A simple cheese way of doing a fuel test is to drop fuel pressure on the regulator like 3-4 PSI and see if it changes the surge your experiencing. But doing this has drivability consequences. So it is always best to have the chips BL tables set to fuel pressure.
Your O2's are going to be high on a non-WB sensor like we have on our cars at part throttle. The 780 target only applies to WOT and time at WOT. As it takes time for heat to build up on the sensor and it to drop numbers. Hence why I always say, look at your O2's top of third gear.
Chris, you are more than welcome to call and discuss the car/issues. As posts/email is very one dimensional.
HTH