An LA 273 isn't an engine, its an Uzzi with with silver bullets!
In NZ, Valiant Regals came out with a 273, and despite its narrow 3.625" bore, it reved and perfromed unlike any other small block V8. The Commander 273 was a standout engine.
BlQQdy Chrylser engineers.
Two things I've seen is that with little I6's or SB V8's,
1. the ones winning have excellent rod ratios of 1.8:1 of better. Over rev capability is the key for production drag racing engines. Even with poor breathing via restrictive 2-bbl carbs, they will haul through the traps at maximum power, often well over 6500 rpm. The 273 and 289's are examples, so are the 240 sixes used in some catagories (2.1:1). The Argentine 188's, just a long block 200 with ultra long rods and a 2-barrel head will rev to 7500 rpm with 300 hp plus with just an IDA.
2. The bore centre to centre spacings should be as big as possible. So a 4.08 centre to centre 188 with a 3.68 bore and 2.94" stroke is passable, but not really good, It's offest by having a good set of 5.4" inch rods give to give a 1.83:1 rod ratio.
The 273 has a 4.56" bore spacing, and over 930 thou between the cyinders. Long 6.125" rods, short 3.31" stoke, 1.85:1 rod ratio.
289 is 1.8:1 rod ratio, but a good 273 outruns a good 289. The 273 is just a narrow bore 340 with unbelieavably solid cylinder walls.
A 300 has a poor rod ratio, but huge bores and a large bore spacing. The rod ratio isn't good. It needs a set of after market 6.8" steel or alloy rods to rev higher without stress.
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