Add me too to the club. Last 2 e-bodies I had this problem were simple fixes. 1971 Challenger was wiper arms pinched under the hood with worn rear hood seal. 1973 Challenger was a vacuum lead down in the heater box. My 70' barracuda makes it when I get off the gas when after 30-70mph. I figure when I tear the car down for restoration, I'll find that problem and be one happy guy again!