Test and tune dates for tracks known for mini-sprint racing around here that I'm familiar with (per track websites)

4/9 - US-24 Speedway
4/9 - Miami County Speedway
4/16 - Plymouth Speedway

From Indiana Sprint Car News

3/5 - Brownstown Speedway
3/12 - Brownstown Speedway
3/12 - Daugherty Speedway
3/18 - Twin Cities Raceway Park
3/25 - Twin Cities Raceway Park
3/26 - Lawrenceburg Speedway
3/26 - Lincoln Park Speedway
4/1 - Bloomington Speedway
4/1 - Twin Cities Raceway Park
4/2 - Lincoln Park Speedway
4/8 - Twin Cities Raceway Park
4/16 - Plymouth Speedway
4/17 - Paragon Speedway