preferred cruising rpm

[Damien B.]

I wanted people's opinion on their preferred cruising rpm.
I will soon get a new 408ci engine, I have a tf727 my gear ratio is 3.73 and my tires are 28 inch so at 60 mph I should be going at something like 3 to 3.2k rpm.
Is it considered too high for some long distance trip.

 

[Red63440]

I have 3.55’s and purchased a diff with 3.23’s to lower the rpm for cruising, should help with gas mileage too. 383, 727 also.

 

[R413]

I don’t like 3K on the freeway.

What torque converter are you using? You want the freeway cruising RPM to be above the stall speed. If not you will build a lot of heat and get terrible gas mileage.

 

[69 Sleeper Bee]

I have a 383 / 727 with a 3.23 gear and at 60mph I am at 2000 rpm.
I do have taller rear tires than stock.

 

[747mopar]

Depends a lot on the complete build but for me it's 2,000 rpm give or take a hundred.

3,000 rpm isn't necessarily to high but for me (mine was right at 3,000) it drove me mad listening to it and it cost me a fortune to drive! Your cam choice will play a part in where your motor is happy and efficient, what rpm range is it? I'm running a stroked 400 with a mild cam with an advertised range of 1,800-5,800 rpm but in reality it's more like 2,000-6,000 and it likes 2,000 rpm. Having a 6 speed I've played around but found at 1,800 it's lugging a bit, 200 more rpm and it all comes into harmony.

 

[440 Charger]

I wanted people's opinion on their preferred cruising rpm.
I will soon get a new 408ci engine, I have a tf727 my gear ratio is 3.73 and my tires are 28 inch so at 60 mph I should be going at something like 3 to 3.2k rpm.
Is it considered too high for some long distance trip.

Have a 440 with 4.30 gears and a 2500 stall not going a gas sipper or highway car lol. But did get another third member to set up with some different gears just incase a trip is needed. That is the advantage of these third members quick to change. Best of luck to you.

 

[Darter6]

I am comfortable with 2000 to 2300 at 65 mph. 2300 seems like a sweet spot for some reason.
Edit;
That is using a stock converter.

 

[Billccm]

I have a 383, 727, 3.23, and my GPS measured speed is 46.6MPH at tach 2000RPM. Tires are P235 60r14.

 

[toolmanmike]

You'll get your best mileage at 2000 rpm or less but your converter and/or cam might not like running that slow.

 

[VitaminCRR]

I have a 383/727 with 3.23 gears and 26 1/2" tires. At 70 mph I'm at 2800 rpm.

 

[440 Charger]

You'll get your best mileage at 2000 rpm or less but your converter and/or cam might not like running that slow.

Remember these are all the fun things to building a car. Make it how you want the fun is personal when you drive it. Sometimes have to settle for ok this works. The perfect part is our forefathers designed these machines and our work is to keep them alive.

 

[diesel_lv]

Well you asked for preferred rpm for cruising, not what I have. It will depend on your cam and what you want for mileage. I'd rather be 2,200 at 80, as everything around me is 75mph interstate. My cam is listed at 1,800-5,800. To do that though, w a 727 n gearvendor o/d and stockish 26.5" diameter tires would require about a 2.72 gear ratio for reference. What I have is 3.73 w 26.5" tires, 727 w gearvendor o/d n I'm at a little over 3k rpm at 80.

 

[copper67sat]

67 Satellite, mostly stock 383/727, 3.23 SG, 14" wheels with 225/70s. Only "long" distance trip it sees anymore is our annual trip up to Daytona Beach for the Turkey Run, about 200 mi. I have no concerns or issues cruising with traffic on I-95 at 80 mph and tach showing 3500-3600 rpm. Car hums right along and usually gets around 14-15 mpg on that trip. Been doing that for nearly 30 yrs.

 

[toolmanmike]

67 Satellite, mostly stock 383/727, 3.23 SG, 14" wheels with 225/70s. Only "long" distance trip it sees anymore is our annual trip up to Daytona Beach for the Turkey Run, about 200 mi. I have no concerns or issues cruising with traffic on I-95 at 80 mph and tach showing 3500-3600 rpm. Car hums right along and usually gets around 14-15 mpg on that trip. Been doing that for nearly 30 yrs.

383's were always pretty good powerplants. That's good mileage for 3500 rpm. 383's have a shorter stroke than a 350 Chevy you know.

 

[Damien B.]

Thanks for the replies.
I m wondering on a gear vendor od but it s quite expensive to import to France and getting the driveshaft cut and balanced with no specialized shop would be a pain, not to mention I would have to change my exhaust line from x to two straight lines unless there is a way to make it fit.

Regarding the cam that will be in the engine i need to recheck edit : Hydraulic roller, duration @ .050: 224 / 230, lift: .565"/.565" 110 LSA. but I think my stallspeed on the converter is around 3k iirc

 

[440 Charger]

Well you asked for preferred rpm for cruising, not what I have. It will depend on your cam and what you want for mileage. I'd rather be 2,200 at 80, as everything around me is 75mph interstate. My cam is listed at 1,800-5,800. To do that though, w a 727 n gearvendor o/d and stockish 26.5" diameter tires would require about a 2.72 gear ratio for reference. What I have is 3.73 w 26.5" tires, 727 w gearvendor o/d n I'm at a little over 3k rpm at 80.

Rpms are fun we cant do lockup convertors if you are looking for gas mileage probly wrong pick change to a 6 speed.

 

[440 Charger]

383's were always pretty good powerplants. That's good mileage for 3500 rpm. 383's have a shorter stroke than a 350 Chevy you know.

Rpms are all gas fun to burn them.

 

[toolmanmike]

Rpms are all gas fun to burn them.

Yep. it's all about smiles per gallon!

 

[440 Charger]

Yep. it's all about smiles per gallon!

For sure these cars are not ment to be sippers but fun as hell to drive. Prefered rpm is a tough one hell 800 but not have to idel at 1100 and cant do lock up converter so is what it is.

 

[BSB67]

Is it considered too high for some long distance trip.

What is your definition of:
1) "some", and
2) "long distance"

My answer changes if it is a 500 mile trip once per month, verses a 250 mile trip 3 times per year.