A couple years ago I installed a Holley carb on my '69 T-bird. The old Autolite just wouldn't run right. After being rebuilt by Pony Carbs it was even worse. To make a long story short, it was swapped out for the Holley. About 6 months ago I started having a strong gas smell after parking the car in the garage. Without taking the aircleaner off, I never noticed any leaks, so I though it might just need some fine tuning. A couple weeks ago I finally got around to solving this problem. Turned out that the gasket for the front fuel bowl was deformed from the factory. Wasn't making a complete seal. I alo changed the power valve thinking it was leaking making the car hard to start after sitting for a couple weeks. That must have made a difference, because it does start easier now and doesn't leave a big black smoke screen when you get on it.