As already mentioned - going up from the floor to the dash would make access to the hood release difficult. Also, that gear shift lever has quite a range of movement out at the level of the dash - you'll either neet to avoid the lever (making any connection from the floor to the dash largely out of sight) or have an improbably large hole in it to let the lever move around. There won't be much room under the dash for gauges either - I have a little 3 gauge pod of 2 inch round gauges centered - and I had to bend the panel they sit on slightly backwards to avoid being touched by the lever when it is up.

Of course, you could always just chop the heck out of the tunnel and put a short shifter top on your transmission.
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I'm JohnMc, and I approved this message.