how much of the tunnel do I cut and raise-1967 camaro with TR6060

[Bullrider]

Looking for advice before we cut our tunnel-my son and I are building a ‘67 camaro using a DSE subframe with a LS3/TR6060 and we modified a transmission crossmember since nobody makes one for this combo. We have the tranny angled down 3 degrees and the front half of the tunnel will have to be raised at least 2-3” to clear. My question is the driveshaft-since I have lowered the rear end, and my tranny is a little high, will I need to raise the back half of the tunnel so the driveshaft will have plenty of clearance? I plan on bolting in the subframe and then ordering the driveshaft so I can see the clearance but wanted to see if anyone else ran into this situation.

[67-LS1]

I would recommend you set your trans angle, the pinion angle of you rearend AND the ride height first. Install the driveshaft too if you have it. If you don’t have the driveshaft yet, you should still be able to eyeball the path required.
I enlarged the tunnel on my 66 Chevelle without following the advice above and am now going to have to go back in and cutout and raise the driveshaft tunnel. Would have been a lot easier all at once.
Don’t forget that if you raise the driveshaft tunnel, you also may need to alter the rear seat frame before upholstery.