Specialized Diesel Parts (SDP) is a family-owned business based in Hot Springs, Arkansas. It was founded by President/Owner Chuck Johnson in 1999 and acquired by the Hilliard family in 2025.
For 25+ years, SDP has been a staple name in the EMD diesel engine market supplying quality OEM and aftermarket spare parts. Today, SDP is proudly a division of the Hilliard Company carrying on Mr. Johnson’s legacy for many years to come.
Our mission is to responsibly manufacture and distribute high quality spare parts in an effort to reduce our client’s operational costs with an emphasis on personalized customer service and timely deliveries.
