robert. wrote:A guy named Andy Koslow made overhead valve conversions for flat head harleys. During the mid. 30's. He also cast a sprocket side motor case for part of the conversion. His heads made so much power poor little Harley cases were cracking. If you can find his stuff today. You hit pay dirt.
Here is a link https://www.hwcclassics.com/1936-koslow-racing-engine/
Call Mike and Frank!