what rpm do you cruise?

[70cuda50]

very subjective question but, what rpm is everyone comfortable cruising at with a 440. I have 4 speed. About to drop in 440. I plan on mostly just cruising on 40-50 mph roads near house on 10-30 minute errands and joy rides, but will occasionally hit short stretches of interstate up to 75. Right now the plan is to go with 3.54 in the Dana. I am mellowing in old age so really don't need the most aggressive launch anymore so cruising is more the priority. Is 4th gear normally a 1.0 ratio? Been using that to run the calculator with 27" tires for various ratios to get rpm at certain speeds, just don't know where the sweet spot is for longevity but still some get up and go.

 

[Rich G.]

Forth gear is 1 to 1. Those gears would be about the highest you’d probably want and still cruise comfortably. 323 are the most common I believe. Probably not in a Dana.

 

[tonysrt]

I have 71 Cuda, 472 Hemi, 354 Dana and 275/60/15's, which are 28", a tremic 5 speed and run 70 at 2000 RPM. I think at 50 I'm around 1500 RPM, but never really pay attention to the lower speeds. I try to get into 5th as soon as possible because the exhaust quiets down in 5th.

 

[704406]

70 Cuda 440-6 auto 3:54 Dana 260/60/15 tires at 70 MPH 3600-3800 RPM engine sounds "busy" exhaust is loud, I'm always looking for another gear (which I don't have) 1 more gear would be wonderful above 60 MPH! 60 MPH is about 3000-3100 RPM which even on a 50 mile drive gets old, lift the throttle and there's no coasting either!
3:54 is about the highest numerical ratio for a Dana 60, there were some early diesel pickups with a 3:07 ratio but if my memory is correct diff case needs to be changed, and I'm sure there is something else that makes a swap to that ratio not practical.
440's have so much torque they launch easily with 3:54 gears and get traction unlike 4:10 where wheel spin is the norm.

 

[70cuda50]

Thanks. That helps. especially at my expected lower speeds being the norm, the 3.54 should be acceptable and still launch well. And even light em up occasionally. I said I was mellowing... not dead . It is a big block mopar afterall.