Air Flow Research's new CNC-ported 300cc cylinder heads are a good upgrade for those smaller cubic inch big blocks. According to AFR, this high-flowing (390 cfm at .700 lift) oval-port head really packs a punch—not only with tremendous air speed from its extremely efficient port design, but also enough total cfm to approach 800 hp in an aggressive combination. Is this a hint we could we see a trend in cylinder head technology where builders opt for high velocity, small port heads?