* Smaller Valves: 305 heads generally have smaller valves than 327 heads. This will restrict airflow and reduce power output compared to using heads designed for the 327.
* Combustion Chamber Design: The combustion chamber design might not be ideal for the 327's piston design, potentially leading to lower compression ratio or even interference issues. You'll need to carefully check this.
* Performance Differences: You'll likely see a noticeable performance decrease compared to using heads specifically designed for a 327.
In short, while it's *possible*, using 305 heads on a 327 is generally not recommended unless it's a temporary solution or you're severely budget-constrained. For optimal performance, find a set of heads designed for the 327. You might find good used options at a reasonable price that will provide better results.
