I used Classic Insturment gauges. I like them.
Here's how I did the install in my 50.
I first gutted the original gauges.(removed bezel and glass then gauges).
I then cut a hole big enough in the original housing to slide the new gauges thru. (5" circle).
I bought new bezels and reinstalled them on the original bucket (now with 5" hole in back) then slide in the new gauges (from the front) making sure they "new gauges" were indexed properly with the way the original aligned up with the dash in the back "studs"
I used the attachment hardware "u-brackets" that came with the new gauges to secure them "new gauges".
Then installed them from the back side using the original brackets on the original gauge onto the studs on the back of the dash.
I hope I didn't confuse you, It was really easy to do and looks almost factory.
