"open 4 barrel intake with tbi adapter"

Morning, I am new to the ecm/pcm/ecu tuning side of the performance world, but a couple of questions.

First, where does the performance lack that you are trying to tune? Low, mid or high rpm?
With a open plenum intake you are going to suffer low to mid-range drivability and performance in most cases.
We found even with carb. streetable engines that dual plane intakes provide much better street manors and performance gains.

Next, has your intake been tapered where the tbi plate bolts to it? The TBI bore is wider then a standard square bore intake and will have sharp edge for the air/fuel mixture to flow around causing a disruption. My dual plane intake is off the engine now and I am tapering that narrow area and rounding out that flow for lack of a better term before transferring that engine into my '94 Suburban and installing the TBI. Have not had my coffee yet.
I have found a 1" spacer that takes into account the narrow square bore pattern and puts the taper in the spacer, but it was pricey. Considering I have access to tools to mod the intake, I am going that route.