Late 60's AMA British Twin Dirt Track TT Racer Weight?

Would anyone know the ready to race weight of a well set up for AMA Pro TT dirt track British twin such as Dick Mann's BSA shown here, probably at Peoria at the end of the 60's. Was there a minimum weight rule at the time? What was the cc limit for the expert OHV TT twins at the end of the 60's?
Bill

pantah_good said:

View attachment 2967 Would anyone know the ready to race weight of a well set up for AMA Pro TT dirt track British twin such as Dick Mann's BSA shown here, probably at Peoria at the end of the 60's. Was there a minimum weight rule at the time? What was the cc limit for the expert OHV TT twins at the end of the 60's?
Bill

Click to expand...

AMA Flattrack displacement limit has been 750cc since before the British Teams were allowed to step up from 500cc ohv vs. 750cc sidevalve (Harley KR) in 1973 and stayed that way until the advent of the "Supertrackers" which were 1000 cc production-based motors in proprietary chassis. They even allowed (imagine that) Harley XL engines of 1200cc, but it didn't help them.

I think the minimum weight limit has always been in the vicinity of 325 lbs and not sure if the singles or 500s got a weight break.