When I bought my truck it already had upper and lower pulleys installed which were putting out 6 more pounds of boost. I was wondering if there was any way to tell what pulleys I have. The upper has 280 imprinted on it so I’m guessing it is a 2.80. I measured the lower, its 8 ½ inches across. So what are mine?
#?upper #?lower

 

4lb lower i believe