tillolson HR 178 a

[jim fair]

I just picked up a nos HR 178 A can anyone tell me if they were all sold as alky carbs . only ones  i can find in old catalogs are listed as Hartman alky  carbs. it has the lower air filter cup  mounting  hole machined off  like it's for a rotary engine to clear the starter nut.  It has a ball check should I change this to a needle and seat. thanks for any help. Jim