Here are some considerations and challenges you may face:
1. Compression Ratio Changes: The 400 SBC heads typically have larger combustion chambers compared to the original 327 heads. This can significantly decrease the compression ratio of the engine, affecting its power and performance. To achieve the desired compression ratio, you may need to use thicker head gaskets or perform additional modifications.
2. Valve Compatibility: The valve sizes and locations in the 400 SBC heads may not match those of the 327 heads. You may need to change the valves, valve springs, and/or valve guides to ensure proper valve operation and to take advantage of the larger ports.
3. Port Misalignment: The intake and exhaust ports on the 400 SBC heads may not align perfectly with the intake manifold and exhaust manifolds designed for the 327 engine. This can lead to reduced flow and performance. Custom modifications to the heads or manifolds may be necessary to achieve proper port alignment.
4. Camshaft Compatibility: The 327 Corvette 350 hp camshaft is designed for use with the original 327 heads and their specific port characteristics. Using this camshaft with the different port sizes and shapes of the 400 SBC heads can result in suboptimal cam timing, reduced airflow, and diminished engine performance.
Overall, while it is possible to install 400 SBC heads on a 327, it requires careful consideration, calculations, and potentially significant modifications to achieve good engine performance and efficiency. It would be advisable to seek the expertise of an experienced engine builder or consult specialized literature on engine modifications to ensure a successful outcome.
