I would contact the guy who rebuilt the trans and see if he will help you.
Are you using a tuned port intake ?
When you put the motor and trans together did the torque converter spin freely with a 1/4" gap before you bolted it to the flywheel ?
On the 700r4 the TV cable is not just a passing gear control like a TH350 trans.
Do you have a center to center distance of 1.094" to 1.125" from the throttle shaft to the TV pivot ?
700r4 TV adjustment:
#1.
The button that the cable hooks to at the carburetor or throttle body must have approximately 1.094" to 1.125" radius from the center of the throttle shaft to the center of the button the cable hooks to.
#2. Looking at the throttle shaft lever from the left side at idle position, approximately 33% of the throttle lever total travel must be to the rear of the throttle shaft centerline. And at wide-open throttle, approximately 67% to the front of the throttle shaft centerline. This will be about ½-inch to the rear and 1 inch to the front of the throttle shaft centerline.
#3. The throttle valve cable must be hooked up in this manner so the pressure will rise faster off idle and slow down at heavy throttle. If the pressure cable is pulled in a more even manner the pressure will be too low at light throttle.
WARNING: PERMANENT DAMAGE WILL OCCUR IF THE T.V. CABLE IS NOT ADJUSTED OR HOOKED UP.
THE DAMAGE WILL OCCUR WITHIN A FEW FEET OF DRIVING THE VEHICLE!
Failure to hook-up the throttle cable in this way will burn the three-four clutch pack up fast.
For this reason most trans shops will not sell a 700r4 rebuild unless they install it in the car and set the TV pressure.
#4. The throttle valve cable controls transmission pressure.
Adjusting this cable is the most important step when installing a 700R4, 4L60 or 200-4R transmission.
#5. The final step is to adjust the throttle valve cable. The cable must be adjusted so it is pulled fully out at wide-open throttle. To make sure disconnect the cable, hold the throttle wide open with your left hand, pull the cable fully out with your right hand and see if the cable end lines up with the button on the throttle lever.
The cable should also be pulled out 3/8 to 1/2 of an inch at idle.
#6.
Do not attempt to adjust the shift timing with the throttle valve cable. The shift timing is controlled by the governor springs and weights.