Just wondering what's the best cruising RPM for a 292 .030? I'm needing to figure out rearend ratio.

 

For fuel economy probably somewhere around 2000-2500rpm. You would have to experiment for yourself to find the sweet spot for your combo.

Without overdrive, 3500rpm should be in the ballpark of 70mph. As long as the engine is in good condition and proper tune, that will be safe.

 

Thanks Charlie,
I'm currently running a C4 auto, 3.50 rear gears and a 275/60/15 rear tire. I was thinking 3,400 to 3,500 RPMs might be a little too much.

 

Like I said, as long as it is in good shape and tune, it will be fine.

Getting the rpm down with a rear ratio change or overdrive will make the engine last longer since it will turn fewer revolutions per mile but it should still last a long time and nothing catastrophic will happen solely as a result of the RPM.

 

Howdy,

I am planning 2100 RPM at 60mph (with OD)

Cheers,

Rick

 

Let me know how yours likes running in the low 2000's.