Really. You need to understand the leakdown tester.
The industry-standard orifice in leakdown testers is a round .040" diameter hole. If a cylinder were to read 50% leakdown, the "leak" would be the equivalent of the air passing through the .040" aperture. So 29% leakdown indicates a leakage path of significantly less area than a .040" diameter circle. Air can't move very quickly through a tiny passage. See for yourself- even at cranking speed, you only show about 5-10 PSI less- about 3-5% lower than cylinders with "good" leakdown numbers. Even at idle, piston speed will be 4-5 times as fast as when cranking. And the impedance of fluid (air) through an orifice increases as the square of its velocity. Without doing the somewhat difficult math, I estimate that the 29% cylinder will suffer about 1% pressure loss- at idle speed!
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Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons?
... or has built a record breaking DOHC hemi four cylinder Pontiac?
... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967)
... or has a Pontiac born the same year as Jim Wangers? (1926} 
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