Installing a 700r4?

Good morning, guys, great video on installing/measuring a custom driveshaft. My question is this, we are installing a 700r4 and removing the 2-speed super turbine. We have a 326 engine. After installing the new transmission and measuring for the new drives haft length, in the video, the new drive shaft was bottomed out in the rear however when bolting it up to the front it had moved out the 3/4". Once the car is lowered on the ground will it bottom back out again? Silly question but just curious and want to make sure when I measure/install mine. Thanks guys. Sincerely, Larry