After losing fuel out of my float bowl after long non op times, thought I'd change the power valve. Read where they can get ruptured and seep gas into intake. The new one from Napa was the same diameter but the opening exposing the diaphragm was bigger? Maybe it doesn't matter but thought I'd check. I know based on elevations there different power valves. Couldn't see any tears since much of old diaphragm was shrouded by the cover. Also replaced needle and seat and accerator diaphragm. Idles fine but will test drive tomorrow. BTW-66 289 C-Code. Thnaks Much