Driveline setup during fab phase

[NorCal-SS]

I’m hoping some experts can chime in. Project details:
- 67 Chevelle with LS/T56 swap
- Hellwig Framefx brace kit
- Holley eng and trans mounts
- original 12 bolt with adjustable upper arms
- no driveshaft yet

I’m at a point where I need to weld in my transmission crossmember mounts and want to make sure I have the eng/trans at an acceptable angle. Understand the T56 will need to be raised substantially and the tunnel sheet metal will be cut. Problem I’m having is ensuring the transmission crossmember mounts are welded in at an acceptable height (especially with no driveshaft yet).


Would it be best to mock everything in place and measure for a driveshaft first? Or set the trans output angle and diff pinion at or near 3 deg?



Thanks in advance for an insight on proceeding !