Briefly, a friend has a 40 Ford coupe rod, unfortunately it has one of those unmentionable engines in it. Anyway, a basic emissions test is required here before a collecter licence is issued. (no, I don't know what standard is used for the tests?) After several failures, with a 600 Edelbrock, a mechanic told him that heat transfer to the carb was causing perculation. The carb spacer is aluminum. I suggested he replace that with an organic spacer as aluminum transfers heat quickly. But, I can't remember the correct name for those old style carb spacers? What was the material called? And are those type readily available now days?

Paul