906 heads

Just for reference. I bought a complete 1968 383 big block with 727 trans for $500.00. I took it all apart, and it looked like someone tried to do a half assed refresh of the motor. I put the set of 906 heads and cast 4bbl intake under the bench.The block was std bore, i sold the crank rods and pistons for $200.00, the heads are clean, looks like the valves have been touched up etc? Do you know if those heads are cracked at all etc. They are going to need hardened exhaust seats to run on unleaded fuel .