Back in the day 1980s i built a rubber rod 455 and intentionally drove it to about 7000 rpm in 1st gear as an experiment, just to see and hear how it would play. Then a month or so later i tore it down and found a rod or 2 bent (Z'd i would say) but did not break, and that was the experiment. Oh heck i pitched the rubber rods and put SD-455 Rods in.
Later on, after 9 1/4 mile runs with late-shift over-revs for High-12s at best, i would spin a SD Rod bearing on the way home from Island Dragway, and chunk that engine. Think I rebuilt it and sold it!
From that i learned that high-RPM is only warranted if the Heads continue to flow. We all got to know our "choked-flow limitation" in the inhale path. Usually is the Pushrod bulge, then the bowl, then well the whole path CSA being some reasonable value. The next project ran 12.0s at 4950 rpm at the big end. 3.31:1 gear with 28" tires, yet needed 94+ -to- 110 LL fuels.
Now the 68 GTO does those 12.0s with 89 Octane, SD-455 rods, and OVERdRIVE. The HP is in the Heads.
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12.24/111.6MPH/1.76 60'/28"/3.54:1/SP-TH400/469 R96A/236-244-112LC/1050&TorkerI//3850Lbs//15MPG/89oct
Sold 2003: 12.00/112MPH/1.61 60'/26"x3.31:1/10"/469 #48/245-255-110LSA/Q-Jet-Torker/3650Lbs//18MPG 94oct
Sold 1994: 11.00/123MPH/1.50 60'/29.5"x4.10:1/10"/469 #48/245-255-110LSA/Dual600s-Wenzler/3250Lbs//94oct
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