Will a set of aftermarket gauges fit in the dash of my 1969 cutlass with no modifications. I would like to buy an autometer in dash tach and be able to put it in the space on the right where there is currently nothing. Also, I am having a slight problem. The dash lights are not right at all. At idle, they dim to where they can barely be seen. What is likely the cause of this. Sorry about all these questions I have been asking, new car and I would like to get it reliable and everything working as soon as possible.