ive got a 062 vortec head 355 with the 268xfi cam currently with a fully ported set of SLP runners a ported SDPC base and port matched plenum.
the car falls on its face at 4900 rpm... i need power to at least 6000RPM
the intake is not letting the engine breath.

i already have a vortec stealth ram [ no fuel rails though] but i have heard alot of mixed opinions about hsr and single plane. fabrication isnt an issue.

can someone link me to dyno results comparing the two of them... i know the hsr will be a big improvement.. but if the single plane stuff is better yet, then i am going to skip right to the good stuff.

Lee

 

with that cam and head combo it really should ony make power to 5500 or so... my 062 vortec heads motor has the xe274 cam and peaks out about 5800-5900 thats with a rpm airgap and 750dp...

i think you be better off with the long runnerd HSR .. it would keep the torque down low and easily keep up to 6000rpm

 

the hsr is more than enough for that combo. Mine, although mildly ported, feeds my 383 to 6300 rpms and starts to fall off around 6500. I think it could support 6500 and I may find out with a bigger cam this winter for next spring