3.35 first gear is OK if you have a 2.88 rear end. I have a 3.31 gearset in the diff and I expect first to be OK only for casual driving; on any autocross it will likely be better to launch the car in second gear to avoid having to shift about 2 seconds after leaving the line.
I’ll post a picture of my trans tunnel mod maybe this weekend. You can judge whether or not you’d be willing to do that to your Tiger. I decided that if I really wanted to then I could bang some sheetmetal into place and rebuild the original lateral bracing.
As it was, a PO had done some other modifications to the bellhousing area to improve access to the bellhousing bolts (presumably for easier engine/transmission removal), and I ended up patching those as well as reversing some other modifications done sometime in the last 40 years. As the owner, the decision of what’s right is yours.