I havent seen many of these but helping a friend build a 6466 Evo.

Had Kelford 272 with no springs but he has a 2.0 with Turbo Tuff, HD Pistons and ect.

Could he benefit from these cams or moving up to GSC S3?

Since he wants to rev higher till around 9000 RPM and install dual springs, valves, and port head?

 

I chose s3 over the s2r for the same reason. I want high rpm power not so much mid range.

 

Do a s3