Built 455

hootsr

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Lesabre
Hi, I have a lasabre with a built 455 and was wondering what a safe highway rpm would be. Also a rough idea on safe max rpm might be.
Engine specs are bellow.thank you
1000005059.webp
 
With your trans and 3.23 rear and 27in tall tire at 60mph your rpms are around 2500. This could vary if you have shorter or taller tires. that would be a safe cruise speed. As for better gas mileage 2000rpms would be better. Cruising at 3000rpms would not hurt the motor but gas mileage would suck.
 
Hi, I have a lasabre with a built 455 and was wondering what a safe highway rpm would be. Also a rough idea on safe max rpm might be.
Engine specs are bellow.thank you
View attachment 49377
Highway you could easily do 3.5k to 4k all day long.
Maximum rpm I would keep below 6k, say 5.7k to 5.8k.
 
@LARRY70GS could probably chime in here and confirm normal rpm ranges.
 
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