[Cliff R]

"Cliff I would bet 130 would even be on the light side of pressures for most folks to use with a SFT that is not as an aggressive a lobe as the HR lobes using a SR."

Skip, keep in mind that we are using hydraulic roller camshafts, and simply substituting a solid roller lifter for the HR's to lighten things up, and take the hydraulic action of the lifters out of the equation. These cams are pretty "aggressive" right off the base circle with no "take up ramp", but work fine with solid lifters and .005" lash set-up.

It's all "theory" until you are out there doing it. My engine lives fine after several years of use now, just made 10 runs last Friday evening and it shows no signs of wanting to quit revving, or loss of power at any rpm.

On two of the runs I made there was ZERO traction available, and the engine spun right past 6000rpms so quick on the launch I couldn't get out of it fast enough. I happened to look down a the tach on one of those runs and saw it go to 6400rpm's.

I took a quick listen after the run, valvetrain was dead quiet, so I figured I didn't smack a piston or bend/break anything.

I've logged enough dragstrip time with high rpm set-ups that I know what happens when your springs go "soft" or there are high rpm issues associated with not enough spring pressure(s).

I used to drag race a 283 SBC that I shifted at 7000rpm's, and went thru right at 7500rpm's. A set of springs that I could afford in those days were good for about 50-60 runs. As soon as I'd here it "crackle" up near the finish line in high gear it was time for another set of springs.

I heard the same deal with my last 455 right at 5800rpm's, where the HR"s just couldn't keep doing what they were supposed to. This "hybrid" set up does NOT exhibit any symptoms associated with not enough spring pressure(s) for the rpm range that I'm running the engine in......Cliff