If you have a clean sheet of paper, you can design something in that addresses the problem. This was not understood even in 1970.
The LS inherited some dims and tooling from the SBC (pitch) but moved toward valve train stability while retaining original 1949 Oldsmobile and Cadillac OHV theory (pushrod, parallel valve, wedge). Chrysler and Ford made a more expensive and complex product to do the same thing: reliable high RPM operation.
GM moved the cam tunnel up, so that the pushrods do two things differently:
1. closer to horizontal (as are tappet openings, and rocker levers)
2. shorter
Pushrod length is also critical to stiffness, except generally there's nothing you can do about it. But sometimes...
Assuming that the inserted ends are each (roughly) .500" long, an RB pushrod at 8.905" (HT: 440 Source) is .750" longer than a B pushrod, with the unsupported tubes (roughly) 7.905" and 7.155". Using 3/8" X .100" wall to limit variables, the stiffness in compression is also highly sensitive to length.
RB 8,426Ω
B 11,897Ω
The otherwise identical B pushrod is 41% stiffer (and lighter).
This will also follow with any engine family with multiple deck heights:
Windsor (4 different)
Rocket and late Oldsmobile
BBC
Nailhead
Chevy Gen-3 L6
Ford big L6
Ford small L6
Gen-1 hemis (all 3 families)
Pontiac
Slant 6
