273 Top End Swap

"302's" have the same chamber volume as the old '920 heads,,,the chamber shape is different, and they have hard seats already. Any small-port 273/318 dual plane intake, such as LD4B or SP2P, works great with the 302's.

302's have the same bolt hole locations as the 920's. When using 302's with stock manifolds, there is some grinding to be done at the back of the drivers head where the exhaust downpipe section passes by the head. You'll need to grind the head as well as the manifold, as just grinding one can cause problems. Also, you need to thread and plug the emission ports on the 302's.