NHRA Top Fuel uses a Hemi?

Aries also used to make Hemi heads to fit Chevy Big Blocks. They were pretty successful back in the late 70's with them, too.

Hemis have been the fuel and alky engines of choice for nearly 50 years. Big Daddy Don, and many others, used to rum 392's before switching to the 426 layout.

The after market Fuel Hemis are just that, purpose built, no water jackets, etc., but, they need to be manufactured to allow a standard set of 426 Hemi heads to bolt down to them. They're also limited to 500 cubes.