I think the ultra-high performance racing gauges are rated to add about 5HP each, so that's 15HP right there. Of course mounting them at the top of the dash adds a little more so all together probably about 20HP. 12's? Please!!! I think I broke all the clocks when I ran my 1/4 - anything under 10 and the clocks just explode.
ON a similar note, have you guys seen those ground wires that pop up on ebay claiming to give you a big HP increase. Here's one:
ebay auction LOL Think about it - even with the minimum HP increase listed there on my car that would be almost an 8% HP increase. WTF? This one's not listed as being for a 210 but I've seen the same claims on the ones for my car. Talk about BS. I'm sure there is some benefit to having a better ground but it really depends on the condition of your ground before installing it. If everything is done up right then this thing will do nothing at all but maybe make your engine bay look a little more colorful (and I know the last thing I need under my hood is more red...)
Michael