[camerjeff]

I was told by "Mac" that GM was worried about warranty issues with the longer stroke 250 OHC-6's and they used weaker valve springs on the 68 & 69 Sprints to limit them to around 5400 RPM by having the valves float at that RPM, the sorter stroke 66 & 67 Sprints will rev beyond the 6500 RPM red line. By putting stronger valve springs on 250's I have been able to get them to over 6800 RPM. but they don't rev as fast or freely as the 230's do.

[azmusclecar]

Originally Posted by camerjeff

I was told by "Mac" that GM was worried about warranty issues with the longer stroke 250 OHC-6's and they used weaker valve springs on the 68 & 69 Sprints to limit them to around 5400 RPM by having the valves float at that RPM, the sorter stroke 66 & 67 Sprints will rev beyond the 6500 RPM red line. By putting stronger valve springs on 250's I have been able to get them to over 6800 RPM. but they don't rev as fast or freely as the 230's do.

Jeff, how do the valves "float"............is it that they just don't seat due to the weaker
spring pressures to keep them sealed in the head? Or are they bouncing due to such high rpms they don't have time to seat?

Sorry if the question is stupid.......