They might have the same casting numbers but there are several with that same casting number. they should have the screw-in studs, machined pockets and cups for the valve springs. that all can be faked. There is another casting mark on the heads, think it's a number in a circle that tells for sure. Veronica knows the right code. Compression ratio on them motors could be 10:1 or even 11.6:1, way too high for todays gas.
2015 Stage 3 Roush
'66' Ranchero w/almost done 302 T-5 swap
2000 4x4 Ranger
2003 4x2 Ranger
'69' Fairlane Cobra, 428 4-speed waiting for work