Help needed: How much of tranny hump should be removed for auto -> manual swap?

[Dakota]

The prior owner changed the transmission on my 70 Challenger from an automatic to a manual.   There were some strategic cuts made in the auto tranny hump (see pic below - sorry, not a great one) for the shift linkage, and then a manual hump was screwed down over it.   This approach seemed to work OK for clearance but it was a major PIA to reach everything during dismantlement.  Also, I think the current arrangement is likely to trap a lot of dirt and maybe some water over time.   I'd appreciate seeing some pictures or explanations of how other members have handled this situation.  Thanks.

[1 Wild R/T]

Drop the hump on the floor, it should pretty much locate itself front to back & side to side...... Use a marker & draw the location on the floor....  Remove the hump & draw a second line 1" inboard of the first.... Thats your cut line...  Accept do not cut the crossmember, leave the floor covering over the crossmember... So you wind up with two cutout areas...

[Chryco Psycho]

I usually mark around the hump & cut 1.5" inside of that , don't cut the T bar crossmember tho

[Dakota]

Thanks guys. 

[RUNCHARGER]

Yup: That gives you lots of room.

[Dakota]

One more question on the same subject: how do you attach the manual hump to the floor?  Prior owner used sheet metal screws and some kind of caulk to seal it. 

[RUNCHARGER]

It is supposed to be spot welded and seam sealed. I have used panel glue and it is fast and easy but you need a special gun that mixes it as you apply it, either that or a welder is best. Screws will be chopping up your digits when working underneath the car. If I didn't care about appearance I would rivet it before using screws.

[ToxicWolf]

I don't know if this will help, but here are some pictures from when Roadman did mine 

[Claudia]

I converted from a manual to automatic but the same steps applies . . . measure twice and cut once.  I just cut out what I thought needed to be removed, formed and welded in some sheet metal pieces in it's place and then seam sealed everything.  Over all, pretty easy process plus I added brackets for a center console.