Conversation so far:
when did Alan Kulwicki start racing?
Alan Kulwicki began his racing career as a 13-year-old kart racer.
who made the karts for Alan Kulwicki when he began his racing career as a 13-year-old kart racer?
Alan Kulwicki's father built engines as the crew chief for Norm Nelson and Roger McCluskey's United States Automobile Club racecars.
when did Alan Kulwicki start racing cars after his father built engines as the crew chief for Norm Nelson and Roger McCluskey's United States Automobile Club racecars?
Alan Kulwicki started driving stock cars at the local level at the Hales Corners Speedway and Cedarburg Speedway. In 1973 he won the rookie of the year award.

Question: did he have any sponsors?
Self-contained rewrite: did Alan Kulwicki have any sponsors around 1973 when he won the rookie of the year award?