I've owned my '63 sprite for about 2 months now and am loving it. my exhaust leak that i was getting to address beat me to the punch. at about 50 mph the down tube came off the clamp at the exhaust manifold and scraped for about 40 yrds. i took it off and drove about 1/2 mile and the engine started running terrible, missing, backfires, not wanting to idle. i put the exhaust puipe back on the best i could witht the flare beat up as it was, and the car is still running like crap. how much of the problem is caused by that exhaust leak? tghanks, Chris