High Hump / Shifter question

[kda2000]

I am working on a 68 stepside project, it currently has 250/3-speed. I want to change it to a 4-speed (SM465), which I have 2 of (and the other related parts that are needed). I'm contemplating swapping in a '68 307 that I also picked up, but I have one question that I have not been able to find an answer to:

Since the V8 mounts forward from the 6-cylinder location, and the 6-cyl is longer, this will move the transmission forward as well. So does the cross member where the bellhousing sits have to be moved forward as well or are there 2 sets of mounting holes? for both a V8 and a 6-cylinder as there is the engine mounts? and are there two different high humps, one for the 6-cylinder shifter position and one for the V8?

I think I have seen the shifter coming up though the flat part of the hump, and other coming up further forward right where it turns up toward the firewall. Is this is 6 vs 8 difference?

Sorry, I guess that's 4 questions. Thanks for any insight you can give me.

Ken