[Dyno]

Aluminum heads are what a group of us petitioned NHRA for 8 years or so ago. We were turned down. NHRA now allow the aluminum head but they are hard to find. The main reason was the heads are more repairable and easier for the head porter to work on. No one wants to work on old cast iron heads anymore! Plus us old guys have a hard time lifting the iron heads on and off the block.