Driveshaft question

[4coil]

We are currently rebuilding a Street stock and wondered if someone could answer a question quicker than having to mock up the complete drivetrain. The engine location rule is #1 spark plug no further back than LF upper ball joint. Metric frame with the wheelbase at 108", using a Falcon tranny, and 9" floater rear, what length driveshaft will we need? A driveshaft came with the car, but it also had the stock 7 1/2" rear so I don't know if we can use it. Thank you all in advance for your time!

[95shaw]

Save yourself expense and headache later. go ahead and mock up. Sometime in the build process you will have everything like you are using it. Then you only have yourself to blame if not correct.

[dirtplay18]

Mock up for sure, try to get the car close to the ride height, and make sure you mock up using the desired length pinion yoke you're going to run.