4 speed conversion floor pan change

[GoMangoBoys]

We just bought a 70 Challenger that was partially converted to a 4 speed.  The tunnel has a new piece added in to accommodate the shifter.  We go it on the lfit tonight so I could really see the underside.  It looks like there is a frame section that goes up over the tranny.  Just curious if this is going to need to change as well.  For what its worth, I think the guy who did the change to the tunnel could have done a better job on the underside, so we will be improving that a bit.  The way he left a big jagged lip where he cut out the hump and added in the flat piece, I think it will trap dirt and moisture and cause premature rust.

[Chryco Psycho]

The crossmember need no modification at all , the factory job was never very clean where the shifter tunnel was added , very little dirt will get up there unless you are running ralleys or driving across fields !!

[larry4406]

Attached are some pictures when I converted my floor plan.  I used an original floor hump that I removed from a donor junked car.

I placed the hump in place, traced it, drew an offset mark equal to the flange width, and retained the floor section to seal the upside of the cross member.

I then seam welded it from below (was on a rotisserie).