Tonight I took a few minutes and put the dash back in just to make sure the back of the gauges missed all the mechanical parts and a/c unit mounted behind the dash. All is well. I still haven't decided where I will mount the tach...definitely not on the column and I'm leaning towards the top of the dash. I figure since the blower scoop already limits the line of site a bit I'll put the tach on the dash behind the blower scoop and not restrict my vision to the right or left. I still have a lot of work to do!