i am looking for a fuel pressure gauge. I like the 52mm greddy gauge but they aren't in psi. Are these gauges accurate? i want to keep all my guages the same thats why i want greddy, i also plan a greddy boost and egt. I want them in white faced. also if you know where i can get the best price that would be helpful. so far i found it for 150$ shipped from a group buy on a subaru site.