Needle Adjustment to Default

Hey guys... I recently just fixed my odometer/tripmeter, and I'm just a little paranoid thinking that my gas needle, and perhaps the temp/oil pressure and voltage meters may be off.

What is the best way going about, making sure that these are accurate readings? The most important to me is the fuel gauge. Thanks for any comments...

I ran into this problem after installing white face gauges, but now I think my fuel gauge is off more than before. :(
 
Didn't take pictures of your gauges before the swap...? Easiest way I would know would be to get another similar stang to fill their tank all the way up, and take a picture. Then you fill your tank all the way up and align it like theirs.