Own 54 kit car with early Volkswagen motor what gas should you use leaded or unleaded?

You should absolutely use unleaded gasoline in your 54 kit car with an early Volkswagen engine. Early Volkswagen engines were designed for leaded gasoline, but using leaded fuel in a modern car is extremely detrimental.

Leaded gasoline damages catalytic converters (if equipped) and oxygen sensors, leading to expensive repairs. More importantly, lead is extremely harmful to the environment and human health. Modern unleaded gasoline is formulated to work correctly in these older engines, and using leaded gas is unnecessary and irresponsible. You may need to adjust your valve clearances slightly more frequently due to the different additive packages, but this is preferable to the far more severe consequences of lead contamination.