Interesting, being speedway's last year for there bikes was 73. In late 73/74 speedway sold the bike division and parts to fox, so i was told. So is your 74's fox/speedway thunderbolts? Also how did you date your speedway bikes by serial # being they are just production numbers and have no dates on the serial #'s. Im not sure what fox did with serial numbers though. Pics are worth a thousand words, prices,condition and completeness would help also if you want to sell them.