Check out Speedway Motors, they have some inline parts. E-bay always has something for a 250/292. Stovebolt Engine Company also has parts along with Cliffords.

194/230/250/292 all interchang parts. The newer 250 with entegral head is on its own with little or no modification parts. These later heads can be swaped for the early head with seperate intake/exhaust. Joe