Time was when a company called Racing Head Service struck fear into the hearts of the competition. If your race motor was sporting a set of heads from these hallowed halls, chances are it was going to be tough to beat. This performance reputation carried over to the street. Heck, even if you had nothing more elaborate than a set of stock iron heads that received the RHS treatment, your ride was a force to be reckoned with.
Fast forward to 2006 (or maybe 2007 by the time you read this) and the RHS name has been resurrected, carrying with it a whole new line of performance headgear, including Pro Elite heads for the most recent LS1-series small-blocks. Naturally RHS has not forgotten its 23-degree small-block roots, offering a vast array of different performance varieties for Chevy's original wonder motor. The new RHS lineup has something for every enthusiast, from cast-iron replacements to full CNC-ported aluminum race heads.
In addition to the small-block, RHS also offers heads for Chevy big-blocks, as well as performance pieces for Ford and even DOHC Acura Integra GSR motors. Naturally we are only concerned about the Bowtie brigade, and more specifically, the Pro Action line, but a brief overview of the other Chevy offerings is definitely worth mentioning, starting with the RHS Pro Torker series. According to RHS, the Pro Torker small-block heads were designed to out-perform all previous iron offerings. Compared to the GM 906 castings, the Pro Torker Vortec heads offer an additional 27 cfm at .500 lift.
Like all the RHS heads, the Pro Torker line features Clean Cast Technology to deliver a superior finish quality and improve port transitions. The Pro Torker heads were designed to provide an exceptional package for classes that require cast-iron heads. To improve compatibility, the heads were designed to accept early or late intake manifolds and valve guides designed to avoid the retainer-to-guide shortcomings associated with OEM Vortec heads.
Stepping past the Pro Torker heads to the Pro Elite series, we find the LS1, LS2 and LS6 offerings. Though the Pro Elite series may well include CNC versions of the conventional small-block heads, for now the only offerings are the 210cc and 225cc port volumes, both of which are available with a 62cc combustion chamber. The aluminum LS-series heads from RHS offer superior flow and power production thanks to precision CNC porting. The CNC porting includes not only the intake and exhaust ports and bowls, but also the combustion chamber.