The Hemi 99 cylinder head, released in 1999, is an exclusive design from Steve Sanchez and Total Flow Products.  It was an improvement over existing fuel heads and met his goal of advancing fuel racing.  His inspiration for the design came from years of developing – and repairing – other brands of cylinder heads. 

The Hemi 99 places the intake valve in a “friendlier” area of the combustion chamber.  Sanchez's years of repairing Hemi heads revealed a trend of severe exhaust-side valve train (valve, rocker arm, pushrod) abuse.  Opening the valve against tremendous nitro-fueled cylinder pressure was pounding the components beyond their capability.  Experience told Sanchez a revised exhaust port could resolve the problem.  He reshaped the port for maximum efficiency at low lifts.  That, plus an earlier lift, would release cylinder pressure faster and reduce valve train abuse.

By the late 90s, fuel teams had been using the same cam for ten years and through three or four cylinder head designs.  They were in a comfortable "camshaft rut," and wanted a new head design.  After trying the new TFP Hemi 99 head, and finding no immediate results, teams gave up on it.  Their comfortable camshaft was opening the Hemi 99 exhaust valve earlier than its highly efficient port wanted.  This released part of the power charge and lowered its efficiency.  All the Hemi 99 needed was a new cam, which would open the exhaust valve later – a concept foreign and undesirable to the crew chiefs.  The Hemi 99 head was so good, especially on the exhaust side, the old cam no longer worked properly – it opened the exhaust valve way too soon.

It wasn’t until Rich and Cliff Bozzelli swapped the fuel heads on their Top Alcohol Dragster for Hemi 99s that other racers took notice.  It was unheard of for an alcohol car, with big chamber heads, to run with fat head engines.  But the Bozzellis did just that.  In 2002, without racing a full schedule, they finished fifth in NHRA national points.

Hemi 99 heads have been finding their way into other race venues, also.  National Truck Puller Association Hemi 99 competitors, notably Mark Stigge, are realizing significant power and durability advantages over other brand heads.