oil pressure guage
 

hey guys im new here. I own a 77 vette. I just bought it from a collecter who owns 12 vetts that has put about 1100 miles on it in 13 years. I have all the documentation. its in very nice condition,but ive had to change a few things because it has been in storage for so long. when I crank it up the oil pressure gauge goes to 30lbs and wont budge off of that. I did the ground test and the needle moves in both directions. I checked the pressure with a mechanical guage and cold its about 60-65 . hot it idles around 35. I changed the sending unit and ordered a new gauge. should I have also ordered the printed circuit board? when I pull the cluster I don't want to have to do it twice. I like to have everything work like its supposed to. thanks for any info peter