Low hump removal/High hump install questions?

[68GMCCustom]

I'm doing a low to high hump swap(? or call it a low to high trans tunnel swap?) and had a couple of questions for those that have done it.

1st, I have cut out the low hump and loosely fitted the used high hump I got from a member here...are there any special details involving fitting it/drilling holes , etc. that I should be aware of?

2nd....whats everyone sealing there tunnels up with? Some type of narrow peel and stick insulation tape? Something like a tube of silicone or some seam sealer? Something else?

I will also be reinstalling my B&M Truck Megashifter to the floor/hump that will get a lot of abuse, and wondered how much that might effect the sealing system used.

[CharlieBrown]

All I did was to notch the low cab for clearance..did not cut the entire opening out.I then fitted the high hump plate over it ....sealed it with camper shell tape and drilled with self tapping screws with rubber washers.

[68GMCCustom]

Thanks for the response. I thought about screws... but have a B&M Megashifter mounted to the new hump (as it was on the old hump)...meaning it would be taking some abuse and I feared the screws wouldn't hold up. I wound up bolting it down after running a large bead of seam sealer in what I was guessing a groove around the inside of the hump made for sealant.