340-360 vs 408-414

273 said

I think I'm starting to get this, I couldn't get why Chev people are running away from 400 Chev rod ratio and we're going towards them. But what I'm starting to see is most 408-414 are engine built mainly for summer toys, street strip or full out drag racing. I guess bore/stroke and rod ratio would be more important in high HP & RPM endurance engines like NASCAR I've been playing around with my dyno software bore/stroke and rod ratio seem to make little differance on final output. But in a daily driver like my Jeep would I see an reduction in engine life say like 10-20%?

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Rod ratio isn't a big deal really. But short pistons, lost ring seal and ring pack stability are huge. Life span is directly related to quality of machining and parts, quality of assembly, and rpms. The higer the rpm the faster the wear and the sooner the freshening is required. Generally, my expectation for a 4" stroke engine is a good service life of 40-50K in a mostly street car with mild gearing. For most cars where I am, that's anywhere from 4 years to forever...lol. Usually if they are going to be daily driven they'll have really mild gearing and/or OD anyway and that extends the life.