The case was an EBay find - the top screws off and any of the mini gauges will drop in (they're 2 1/2" I believe)
Easy hook up of these tachs to the coil:
the top connector on the coil where the Black/Yellow wire connects to ign module and is the fire trigger
the bottom connector with the orange/white wire goes to the battery (actually the ing switch) and is the power wire.
on the Barrons tach you have 4 wires - green for the trigger wire - this connects to the top connector of the coil, a red and a blue wire - one is for the tach light(blue one I think) and the other the one is for + battery connection (red i think) connect both of these to the bottom connector of the coil which is the hot wire, the other wire is black and this goes to ground - I just connected this to one of the bolts that holds the coil to the frame.
by the way is pretty important to get good connections here or the tach will bounce around or the engine will die on you if the spade connector vibrates lose - i used tin plated twin tail spade connectors from a boat store - these fit tight and do not rust as quickly.
this is the one I used but I see them on ebay for about $45 or so
http://www.phatperformanceparts.com/ProductDetails.asp?ProductCode=BA%2D7564%...