The biggest difference between the Tomei, Jun and HKS cams is the lift with Tomei at 11.5, Jun at 10.8 and HKS at 10.2. The lower lift HKS cams do not necessitate a valve spring/retainer upgrade but the higher lift cams from Jun and Tomei do. The HKS cams also use a centerline that is different than the more race oriented cams from Jun and Tomei. Theoretically a set of Tomei/Jun 264 cams can should more power under the curve than a set of HKS 280 cams.

Tuning is the key to get the most out of these cams.