* Valve size: While the bolt pattern matches, the valve size *might* differ slightly between specific years and head castings of the 305 and 307. This could impact performance and potentially require adjusting pushrods.
* Exhaust port size/shape: Minor differences could exist here, potentially affecting exhaust flow. Again, this might not be a major concern, but something to be aware of.
* Intake manifold: You'll need an intake manifold compatible with the heads you choose. While the heads fit, using the wrong intake will prevent the engine from running.
In short, while physically fitting, you should be prepared for potential minor adjustments. If aiming for optimal performance, confirming compatibility based on specific casting numbers of the heads and the intended application is recommended.
