Appears to be an early 64 carb, mostly on the C body 413's I understand, but would probably work on several big blocks such as a 383 or 426. Stamp code is difficult to read but I believe it says C4 below the 3858.
Carb has been sitting, will need kit. Secondaries may be frozen so will need freed when rebuilding. $90 shipped anywhere is US. PayPal or Postal MO.