here are some pictures of hardtops at vallejo calif during the 60s and after they went to 305 cu max OHV motors. were flatheads in the 50s. i spent alot of saturday nights there. pitted for bob newkirk & kieth hanson and spent many weekday evenings fixing what they broke on saturday nights. lots of fun and memories.... don
http://vallejospeedwayhardtops.homestead.com/
https://www.youtube.com/watch?v=git3uhP4MEk