Exhaust Flange studs obsulete ?

[craig113]

84 K30 CC 454
Having problems finding a 3 set of flange bolts that bolt the heat riser to the 2.5 inch pipe. Passenger side.
Have been to 3 parts stores and not one of them have see such a stud.
Called Summit Racing and they said that they "do NOT" carry the right studs anymore, " Hope you can find a parts sore in your area and blow the dust off the box."
Does somebody know of an updated part number that will replace these?

3/8-16
1/2" thread then 1/2" shoulder to raised lip then 2" shoulder and then 1" thread.